A pouring device for alloy castings using lost foam casting

Abstract

The utility model belongs to lost foam casting technical field especially relates to a kind of pouring device for alloy casting lost foam casting, it includes: sprue cup, buffer cavity, direct sprue and air extraction device;The sprue cup, buffer cavity and direct sprue are sequentially connected from top to bottom, and the inner diameter of the buffer cavity is greater than the inner diameter of the bottom of the sprue cup and the inner diameter of the direct sprue;The buffer cavity is connected with the air extraction device, and the air extraction device is used for air extraction in sand box before pouring.The utility model sets up the buffer cavity with the inner diameter greater than sprue cup and direct sprue, and directly connects it with air extraction device;Buffer cavity provides chamber for the gas formed by the rapid gasification of model, weakens the pressure of gas, avoids high pressure directly to back into sprue cup and causes back spray.And buffer cavity is connected with air extraction device, before pouring and at the initial stage of pouring, air extraction device can directly and centrally aim at this area and extract air, so that it becomes a negative pressure area, and efficiently collects and discharges a large amount of gas generated in initial stage.

Description

Technical Field

[0001] This utility model belongs to the field of lost foam casting technology, and in particular relates to a casting device for lost foam casting of alloy castings. Background Technology

[0002] Lost foam casting (also known as solid foam casting) is a near-net-shape casting technology widely used in the production of alloy castings due to its significant advantages such as high precision, flexible design, and clean production. The process typically involves impregnating a foam plastic model cluster with refractory coating and drying it, then embedding it in a specially designed sand box and compacting it with dry sand vibration. Molten metal is then poured in under negative pressure, causing the model to vaporize and be replaced by the molten metal, ultimately forming the casting. During the pouring process of lost foam casting, the model rapidly vaporizes and decomposes upon contact with the high-temperature molten metal, generating a large amount of gas. If this gas cannot be promptly and smoothly discharged by the extraction system, it will rapidly accumulate in the runner or cavity, causing a sudden increase in pressure and violent backflow, ejecting molten metal and sand from the pouring cup. This not only seriously threatens the safety of operators but also leads to quality problems in the casting, such as porosity, flame defects, and carbon defects, and may even cause casting failure and production interruption.

[0003] Therefore, there is an urgent need for a pouring device that can prevent backflow, thereby ensuring the safety of the pouring process and the stability of the casting quality. Utility Model Content

[0004] The purpose of this utility model is to provide a casting device for lost foam casting of alloy castings, so as to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A casting apparatus for lost foam casting of alloy castings includes: a pouring cup, a buffer chamber, a sprue, and an air extraction device; the pouring cup, buffer chamber, and sprue are connected sequentially from top to bottom, and the inner diameter of the buffer chamber is larger than the inner diameter of the bottom of the pouring cup and the inner diameter of the sprue; the buffer chamber is connected to the air extraction device, which is used to extract air from the sand box before casting.

[0006] As a further improvement of this utility model, a filter plate is provided at the inner bottom of the pouring cup, and the filter plate is detachably connected to the pouring cup.

[0007] As a further improvement of this utility model, the inner bottom of the pouring cup is provided with a plurality of support blocks along its circumference, the upper part of the plurality of support blocks is in contact with the bottom of the filter plate; and the distance between the end of the support block and the central axis of the pouring cup is less than the radius of the filter plate.

[0008] As a further improvement of this utility model, a conical block is provided in the middle of the filter plate. The conical block is cone-shaped, and the top of the conical block smoothly transitions to its side wall.

[0009] As a further improvement of this utility model, the air extraction device includes an air extraction pipe and a vacuum pump. The ends of the air extraction pipe are respectively connected to the vacuum pump and the buffer chamber, and a control valve is provided on the air extraction pipe.

[0010] As a further improvement of this utility model, an exhaust valve is provided on the vertical pipe of the extraction pipe.

[0011] As a further improvement of this utility model, the top of the pouring cup is provided with a cover plate.

[0012] As a further improvement of this utility model, the top of the pouring cup is hinged to the cover plate by a hinge or a pin.

[0013] The beneficial effects of adopting the above technical solution are as follows: This invention features a buffer chamber with an inner diameter larger than that of the pouring cup and the sprue, directly connected to an extraction device. The buffer chamber provides a space for the gas rapidly vaporizing from the model, reducing gas pressure and preventing high pressure from directly pushing back against the pouring cup and causing backflow. Furthermore, the connection between the buffer chamber and the extraction device allows for direct and concentrated extraction of gas from this area before and during the initial pouring stage, creating a negative pressure zone that efficiently collects and removes the large amount of gas generated in the initial phase.

[0014] This utility model has a unique and reasonable design that can actively guide and exhaust gas, prevent backflow, greatly improve operational safety, effectively avoid quality problems caused by poor exhaust such as porosity, backfire, and carbon defects in castings, and significantly improve the internal quality and yield of castings. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a main sectional view of the pouring cup and buffer cavity of this utility model; Figure 3 for Figure 2 Enlarged view of point A; The markings in the diagram are as follows: 1. Pour cup, 2. Buffer chamber, 3. Sprue, 4. Filter plate, 5. Support block, 6. Conical block, 7. Evacuation pipe, 8. Control valve, 9. Exhaust valve, 10. Cover plate. Detailed Implementation

[0016] To better understand the purpose, structure, and function of this utility model, a clear and complete description of this utility model will be provided below in conjunction with the accompanying drawings.

[0017] like Figures 1-3 The diagram shows a casting apparatus for lost foam casting of alloy castings, comprising: a pouring cup 1, a buffer chamber 2, a sprue 3, and an air extraction device; the pouring cup 1, the buffer chamber 2, and the sprue 3 are connected sequentially from top to bottom, and the inner diameter of the buffer chamber 2 is larger than the inner diameter of the bottom of the pouring cup 1 and the inner diameter of the sprue 3, as shown. Figure 1 As shown; the buffer chamber 2 is connected to the air extraction device, which is used to extract air from the sand box before pouring.

[0018] The pouring cup 1 is wider at the top and narrower at the bottom. A filter plate 4 is provided at the inner bottom of the pouring cup 1. The filter plate 4 is detachably connected to the pouring cup 1. The filter plate 4 filters the molten metal, effectively intercepting solid impurities generated during smelting, transfer, and pouring within the pouring cup 1. Furthermore, it divides the molten metal into multiple fine streams, reducing the kinetic energy of the liquid, minimizing direct scouring of the mold, reducing the rate of mold vaporization, and preventing backflow. Further, a conical block 6 is provided in the middle of the filter plate 4. The conical block 6 is cone-shaped, and its top smoothly transitions to its sidewall. The conical block 6 guides the liquid flow and disperses the impact, further enhancing the anti-backflow effect.

[0019] In this embodiment, the inner bottom of the pouring cup 1 is provided with a plurality of support blocks 5 along its circumference, and the upper part of the plurality of support blocks 5 contacts the bottom of the filter plate 4; and the distance between the end of the support block 5 and the central axis of the pouring cup 1 is less than the radius of the filter plate 4. That is, the filter plate 4 is placed on the upper part of the support blocks 5, which facilitates the later maintenance and replacement of the filter plate 4.

[0020] In addition, the top of the pouring cup 1 is provided with a cover plate 10, which is used to close the cover plate 10 after the liquid is poured to prevent the molten metal from splashing out; in this embodiment, the top of the pouring cup 1 and the cover plate 10 are hinged together by a hinge or a pin.

[0021] The buffer chamber 2 is flat at the top and bottom and spherical in the middle, which achieves a smooth transition, avoids turbulence or air entrapment in the liquid flow, and ensures the quality of the casting; at the same time, it reduces the resistance to gas discharge, so that the gas extraction device can extract the gas more efficiently.

[0022] Specifically, the air extraction device includes an air extraction pipe 7 and a vacuum pump. The ends of the air extraction pipe 7 are connected to the vacuum pump and the buffer chamber 2, respectively, and a control valve 8 is provided on the air extraction pipe 7. Furthermore, an exhaust valve 9 that allows air to pass through and blocks liquid is provided on the vertical pipe of the air extraction pipe 7. The air extraction pipe 7 is made of high-temperature resistant metal material.

[0023] Before and during the initial pouring stage, the cover plate 10 is closed, the vacuum pump is started, and the evacuation pipe 7 extracts the gas from the mold cavity, reducing the pressure inside the cavity. Then, the cover plate 10 is opened and molten metal is poured into the pouring cup 1. Under the diversion effect of the filter plate 4 and the conical block 6, the scouring of the mold is reduced. The gas generated by the vaporization of the mold that is not removed by the evacuation system enters the buffer chamber 2, where the pressure is weakened, preventing the high pressure from directly pushing back into the pouring cup 1. The gas is then extracted through the exhaust pipe, thus efficiently collecting and removing the large amount of gas generated in the initial stage. This prevents backflow, greatly improves operational safety, and enhances the internal quality and yield of the casting.

[0024] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A casting apparatus for lost foam casting of alloy castings, characterized in that: It includes: The pouring cup (1), buffer chamber (2), sprue (3), and air extraction device are connected sequentially from top to bottom, and the inner diameter of the buffer chamber (2) is larger than the inner diameter of the bottom of the pouring cup (1) and the inner diameter of the sprue (3); the buffer chamber (2) is connected to the air extraction device, which is used to extract air from the sand box before pouring.

2. The casting device for lost foam casting of alloy castings according to claim 1, characterized in that: The bottom of the pouring cup (1) is provided with a filter plate (4), which is detachably connected to the pouring cup (1).

3. The casting device for lost foam casting of alloy castings according to claim 2, characterized in that: The bottom of the pouring cup (1) is provided with a plurality of support blocks (5) along its circumference, and the upper part of the plurality of support blocks (5) is in contact with the bottom of the filter plate (4); and the distance between the end of the support block (5) and the central axis of the pouring cup (1) is less than the radius of the filter plate (4).

4. The casting device for lost foam casting of alloy castings according to claim 2, characterized in that: The filter plate (4) has a conical block (6) in the middle. The conical block (6) is cone-shaped and the top of the conical block (6) is smoothly connected to its side wall.

5. The casting device for lost foam casting of alloy castings according to claim 1, characterized in that: The air extraction device includes an air extraction pipe (7) and a vacuum pump. The ends of the air extraction pipe (7) are connected to the vacuum pump and the buffer chamber (2) respectively, and a control valve (8) is provided on the air extraction pipe (7).

6. The casting apparatus for lost foam casting of alloy castings according to claim 5, characterized in that: An exhaust valve (9) is provided on the vertical pipe of the extraction pipe (7).

7. The casting apparatus for lost foam casting of alloy castings according to claim 1, characterized in that: The top of the pouring cup (1) is provided with a cover plate (10).

8. A casting apparatus for lost foam casting of alloy castings according to claim 7, characterized in that: The top of the pouring cup (1) is hinged to the cover plate (10) by a hinge or pin.

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