JPH0344132B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a molten metal filtering device, and more particularly to a filtering device suitable for filtering molten metal when it is poured into a mold. be. More particularly, the present invention relates to a hollow truncated conical filter having multiple slot openings of uniform width for separating particulate impurities from molten metal.

The filter can be placed inside an injection cup having an outlet port that mates with the inlet port of the mold. The slot openings are arranged longitudinally around the conical face of the filter and are of staggered lengths;
This results in relatively fewer slots extending into the smaller diameter portions of the filter than slots extending into the larger diameter portions of the filter. The bottom of the filter has a number of openings with dimensions approximately equal to the width of the slot openings. The top of the filter is open and a flange is arranged around this periphery to join the lip of the injection cup. The filter and injection cup are made from refractory or ceramic materials that have sufficient heat resistance and strength to withstand the heat and impact of molten metal.

Filters for molten metal have been known in the art; however, their usefulness has been limited by the substantial limitations of their metal flow rates, the difficulties encountered in their use, and/or the limitations of their molds. It has been limited by the tendency to introduce unnecessary foreign matter into it. Filters currently in use generally consist of disc-shaped members that are cemented or grouted into the inlet port of a mold. If cementing or grouting is not done with sufficient care, molten metal can swirl around and flow around the filter element. Furthermore, during insertion, grouting or cementing material may enter the mold as fine particles, which cannot be removed once the filter is in place. Can not. Therefore, non-metallic inclusions are trapped inside the mold and contaminate the casting. Three types of disc filters are commonly used. The first, known as the filter core, is made by compressing a ceramic plate with a set of holes. Due to the limitations of the compaction process, it is not possible to obtain larger than 50% open area holes. This results in significant restrictions on metal flow, making the filter core unusable for back flow precision casting. The second type of filter is a foam ceramic with an open cellular structure. As in the case of filter cores, this type of filter cannot be used for backflow precision casting.
This is because the restrictions on flow are too great. A third type of filter has a screen-like appearance and is made from extruded ceramic. The open area can be as high as 70% and this type of filter has therefore become popular in foundries. However, because this product is flat and lightweight, the limitations inherent in cementing or grouting the filter into the inlet port of the mold as described above prevent its complete acceptance. I'm reading.

SUMMARY OF THE INVENTION The present invention overcomes the limitations inherent in prior art molten metal cast filters by including a hollow truncated conical filter having multiple slot openings of uniform width. lies within an injection cup having an outlet port mated with an inlet port of the mold, or lies directly within an inlet port of the mold. It can be overcome by

The filter, such as a funnel, is shaped like a truncated cone and lies either inside the injection cup or directly inside the inlet port of the mold, so that the filter can be cemented to the inlet port. There is no need to pour or grout, so there is no risk of cement or grout getting into the mold or of molten metal bypassing the filter. By providing multiple slot openings and using a high surface area truncated cone shape, the filter has a high open area, allowing a relatively free flow of molten metal through the filter. Try to forgive.

Therefore, one of the disadvantages of the prior art is that it is adapted to be used at the inlet port of the mold;
It is an object of the present invention to obtain an improved filter for molten metals which avoids this and yields improved results.

It is another object of the present invention to provide a molten metal filter device that can be utilized without the need for cementing or grouting the filter onto a mold.

It is yet another object of the present invention to provide a molten metal filter apparatus having a high open area to permit relatively unrestricted flow of molten metal through the filter.

It is yet another object of the invention to provide a molten metal filter device suitable for use in counterflow precision casting.

According to the invention, it consists of a hollow truncated conical refractory or ceramic filter having an inlet port and having a number of slot openings of uniform width around its conical surface. A filter device is provided.

In one particular exemplary embodiment demonstrating the objects and features of the present invention, the slot openings are longitudinally aligned and of staggered lengths, thereby: There are relatively fewer slots extending into the smaller diameter portion of the filter than slots extending into the larger diameter portion of the filter. The bottom or smaller end of the filter has a number of openings sized approximately equal to the width of the slot openings. A filter can also be used in conjunction with an injection cup at the inlet port of the mold. The top or larger end of the filter is completely open, and to aid in positioning the filter,
Flanges may be arranged around its periphery.

Description of the Recommended Embodiment Reference is first made to FIGS. 1-3. The figure shows a truncated conical filter 12 which has a conical surface 13 having a number of slotted openings 16 and an open end having an inlet port 20. It includes a top end 18, a bottom end 22 having a number of openings 24, and a flange 16 arranged around the periphery of the top end 18.

The slot opening 16 is a truncated conical filter 1.
2 and are of staggered lengths, thereby extending to the smaller diameter portion of the truncated conical filter 12. The slot that is
There should be relatively fewer slots extending into the larger diameter portion of the truncated conical filter 12. By staggering the slot openings 16 in this way, the maximum number
3, and this slot opening 16 has a uniform width. Bottom opening 24 in bottom end 22 has a dimension approximately equal to the uniform width of slot opening 16. The bottom aperture 24 is readily formed with a circular profile, but could equally well take on other shapes, as can the slot aperture 16, for example. Although any suitable size may be utilized, a size of approximately 12.7 mm (0.5 inch) has been found to be suitable for filtering most molten metals. Since the largest portion of contaminant material in molten metal is by far generally circular and not rod-shaped, the use of slotted apertures, rather than circular apertures, substantially reduces the filtration effectiveness of the device. substantially increases the total flow area without reducing it.

Reference is now made to FIG. 4, which shows that a truncated conical filter 12 can be used in conjunction with the injection cup 14, thereby providing a truncated conical filter 12. The flange 26 of the conical filter 12 is located at the upper lip 30 of the injection cup 14.
We are starting to come into contact with people. Injection cup 14
is the conical surface 13 of the truncated conical filter 12
and an injection cup 1 through which the molten metal can flow.
The dimensions are such that there is a chamber 28 between the inner surface of 4 and the inner surface of 4. Inlet cup 14 has an outlet port 32 through which molten metal can exit.

As seen in FIG. 4, in use, the filter 12 and injection cup 14 assembly 10 is placed over a mold 34 having an inlet port 36, thereby , such that the outlet port 32 of the injection cup 12 engages the inlet port 36 of the mold 34. The molten metal is passed through a truncated conical filter 12
is injected through the inlet port 20 of the injector, flows through the slot opening 16 and the circular opening 24 into the chamber 28 of the infusion cup 12, and exits through the outlet 32. Particulate impurities having dimensions greater than the width of the slot opening 16 are retained within the truncated conical filter 12.

truncated conical filter 12 and injection cup 14
The can be made of any material, especially ceramic or refractory material that has sufficient thermal resistance and strength to withstand the heat and impact of the molten metal being injected. For example, the frusto-conical filter 12 and injection cup 14 may be made of fused silica and zircon, aluminum silicate, or zirconia. Truncated conical filter 1
2 is preferably manufactured by injection molding. Thus, as seen in FIG. 6, the slot opening 16 may be tapered to facilitate casting. Alternatively, the truncated conical filter 12 can be manufactured by mud casting or pressing.

The embodiments described herein are merely for the purpose of disclosing the invention, and those skilled in the art will appreciate that the invention may be implemented with, for example, diagonally extending slot openings or other configurations. Please understand that you can Therefore, partial modifications, variations and substitutions of the embodiments are intended to be included in the foregoing disclosure. It is therefore noted that the claims should be viewed broadly and considered consistent with the scope of the invention.

[Brief explanation of drawings]

1 is a plan view of a hollow truncated cone filter according to the present invention showing the slot opening, inlet port, bottom opening and flange; FIG. 2 is a top view of the truncated cone filter of FIG. 3 is a bottom view of the truncated conical filter of FIG. 1; FIG. 4 is a partially cutaway front view showing the pouring cup placed over the mold while molten metal is poured; FIG. Figure 5 is a cross-sectional view taken along line 5-5 in Figure 1 of the truncated conical filter shown in Figure 1, and Figure 6 is a cross-sectional view of the truncated conical filter taken along line 6-6 in Figure 2. FIG. 3 is a cross-sectional view of the filter. 12... Filter, 13... Conical surface, 14... Injection cup, 16... Slot opening, 18... Top end,
20... Inlet port, 22... Bottom end, 24... Opening,
26...flange, 28...chamber, 36...inlet port.

Claims (1)

[Claims] 1. A hollow truncated conical filter for selectively suppressing particulate impurities in molten metal, the filter having a number of slot openings of uniform width and A molten metal filter device having an inlet port. 2. The molten metal filter apparatus of claim 1, further comprising an inlet cup for receiving said filter, said inlet cup having an outlet port adapted to mate with an inlet port of the mold. . 3. The molten metal filter apparatus of claim 1, wherein said slot openings are arranged longitudinally around a conical surface of said filter. 4. said slot openings are of staggered lengths, such that slots extending into a smaller diameter portion of said filter are smaller than slots extending into a larger diameter portion of said filter; 4. A molten metal filter arrangement according to claim 3, wherein the number of molten metal filters is relatively reduced. 5. The molten metal filter apparatus of claim 3, wherein the bottom of the filter has a number of bottom openings sized approximately equal to the width of the slot openings. 6. The molten metal filter device of claim 5, wherein the bottom opening is circular. 7. The molten metal filter device of claim 1, wherein the top of the filter has flanges arranged around its periphery. 8. The molten metal filter device according to any one of claims 1 to 7, wherein the device is made of a refractory material. 9. A molten metal filter device according to any one of claims 1 to 6, wherein said device is made of ceramic material.