A vortex finder blank and a casting method

Abstract

The application discloses a vortex finder blank and a casting method in the technical field of vortex finder casting technology, and the vortex finder blank comprises a wax mold and a core in the middle of the wax mold, and the core divides the wax mold into two parts. A plurality of blade profile grooves for forming blades are arranged on the surface of the core in an equidistant manner around the axial center of the wax mold. A through hole for connecting the upper and lower parts of the wax mold is arranged in the middle of the core. A riser is formed at the top of the wax mold, and a through hole is arranged in the center of the core to connect the top chamber and the bottom chamber of the shell. The through hole plays the role of the riser and performs feeding for the bottom chamber. Meanwhile, the molten metal in the through hole feeds the bottom chamber downward. The feeding direction is the same as the direction of gravity. Compared with the conventional method of feeding by arranging a riser at the bottom of the shell, the feeding effect of the bottom chamber of the inner cavity of the shell is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of vortex casting technology, specifically to a vortex blank and casting method. Background Technology

[0002] Swirlers are mainly used to adjust the fuel-air ratio in the combustion chamber of an aero-engine and to form vortices to fully mix compressed air and fuel. Therefore, the dimensional accuracy requirements for swirlers are high during production. In addition, due to the small size and complex structure of the swirler's inner cavity, the precision casting process generally uses a core to form the inner cavity of the swirler.

[0003] When the core is used to form the interior of the vortex, the core divides the wax model into upper and lower parts. The upper and lower parts of the wax model are connected only through the leaf-shaped holes opened on the surface of the core. Therefore, traditional vortex wax models have risers at both the top and bottom. After forming, the mold shell is divided into a top chamber and a bottom chamber by the core. Both the top and bottom of the mold shell have risers for molten metal to enter, which are used to feed the top chamber and the bottom chamber respectively.

[0004] During the casting process, molten metal enters the inner cavity of the mold shell through the top and bottom risers. Since the core is placed horizontally inside the mold shell, the molten metal entering through the top riser first accumulates on the top surface of the core. Due to the leaf-shaped holes in the core, the molten metal then flows from the leaf-shaped holes towards the bottom chamber. Meanwhile, the molten metal entering through the bottom riser slowly fills the bottom chamber from the bottom. The molten metal that first entered through the top riser and the molten metal that first entered through the bottom riser converge at the bottom of the leaf-shaped holes. The two streams of molten metal with the lowest temperature converge at the bottom of the leaf-shaped holes. The high-temperature molten metal that enters later in the top chamber cannot fill the bottom chamber through the leaf-shaped holes, and the molten metal that enters later in the bottom riser cannot fill the bottom of the leaf-shaped holes due to gravity. This results in a loose blade root defect in the formed vortex tube, leading to a low yield.

[0005] Based on this, the present invention designs a vortex generator blank and a casting method to solve the above problems. Summary of the Invention

[0006] To achieve the above objectives, the present invention provides the following technical solution: a vortex blank, characterized in that: the vortex blank includes a wax model and a core in the middle of the wax model, the core dividing the wax model into upper and lower parts; a plurality of blade-shaped grooves for forming blades are formed on the surface of the core, the blade-shaped grooves being evenly distributed around the axial circumference of the wax model on the surface of the core; a through hole for connecting the upper and lower parts of the wax model is formed in the middle of the core; a riser is formed on the top of the wax model.

[0007] As a further embodiment of the present invention, the through hole has a circular cross-section, and the axis of the through hole coincides with the axis of the wax model.

[0008] A method for casting a vortex generator, applicable to the aforementioned vortex generator blank, characterized in that the casting method includes the following steps:

[0009] Step 1: The wax model and core are formed into a complete blank;

[0010] Step 2: Apply slurry and sand to the blank, and melt the wax mold part by heating at high temperature to form a shell with an internal core;

[0011] Step 3: Install the mold shell and gating system. Through the gating system, pour molten metal into the inner cavity of the mold shell from the riser at the top of the mold shell. The molten metal enters the bottom of the mold shell through the through hole in the middle of the core and fills the mold shell from the bottom up.

[0012] Step 4: After the molten metal cools down, remove the surface shell and the internal core;

[0013] Step 5: Remove excess metal from the center of the formed vortex generator by machining.

[0014] As a further aspect of the present invention, the blank forming method in step 1 is as follows: the core is processed and formed separately, and during the wax mold pressing process, the core is placed in the pressing mold and pressed as a whole to form the vortex blank.

[0015] As a further embodiment of the present invention, the molding method of the shell in step 2 is as follows: the molded vortex blank is immersed in slurry so that there are no dead corners on the surface of the blank, the sand is adhered to the surface of the blank through the slurry, and finally the whole is heated at high temperature to solidify the sand into a block to form a shell. The wax mold melts during the high temperature heating process, so that a cavity is formed inside the shell, and the core is suspended horizontally in the inner cavity of the shell.

[0016] As a further embodiment of the present invention, the method for installing the shell in step 3 is as follows: several processed shells are arranged and installed in the gating system according to the shape of the gating system.

[0017] As a further embodiment of the present invention, the method for removing the shell and core in step 4 is as follows: after the molten metal cools and forms, the shell on the surface of the vortex generator is removed by vibration shell removal or high-pressure water shell removal machine, and finally the core is washed with alkaline solution under high temperature and high pressure environment to dissolve and fall off the core.

[0018] As a further aspect of the present invention, the method for removing excess metal in step 5 is as follows: removing excess metal from the center of the eddy current generator by machining and drilling.

[0019] The present invention has the following beneficial effects:

[0020] This invention connects the top and bottom chambers of the shell by creating a through hole in the center of the core. The through hole acts as a riser, feeding the bottom chamber. Simultaneously, the molten metal in the through hole feeds downwards into the bottom chamber, feeding in the same direction as gravity. Compared to traditional methods of feeding by creating a riser at the bottom of the shell, this invention significantly improves the feeding effect on the bottom chamber of the shell cavity. Furthermore, since a bottom riser is no longer needed for feeding at the bottom of the core, only a top riser is required. The gating system can eliminate the need for a gating channel that feeds molten metal from the bottom riser, reducing heat loss during the flow of molten metal in the gating channel and lowering the pouring temperature. This helps reduce the degree of interfacial reaction between the core and the master alloy, improving the surface quality of the throat. Additionally, the ceramic core becomes smaller after being opened, making subsequent core removal easier.

[0021] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the overall process of the present invention;

[0024] Figure 2 This is a schematic diagram of a traditional blank structure cross-section;

[0025] Figure 3 This is a schematic cross-sectional view of the blank structure of the present invention;

[0026] Figure 4 A schematic diagram of the cross-sectional shape of the shell after the blank is formed according to the present invention.

[0027] Legend:

[0028] 1. Wax mold; 2. Core; 3. Leaf groove; 4. Through hole; 5. Riser. Detailed Implementation

[0029] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0030] Please see Figure 1-4The present invention provides a technical solution: a vortex blank, the vortex blank including a wax mold 1 and a core 2 in the middle of the wax mold 1, the core 2 dividing the wax mold 1 into upper and lower parts; the surface of the core 2 is provided with a plurality of blade grooves 3 that are vertically connected for forming blades, the blade grooves 3 are arranged at equal intervals around the axial circumference of the wax mold 1 on the surface of the core 2; the core 2 is provided with a through hole 4 in the middle for connecting the upper and lower parts of the wax mold 1; a riser 5 is formed on the top of the wax mold 1.

[0031] In this embodiment, by opening a through hole 4 in the middle of the core 2 and retaining only the riser 5 at the top of the wax model 1, after the blank is formed into a shell, the core 2 will be suspended in the middle of the shell cavity, dividing the shell cavity into a bottom chamber and a top chamber. The riser 5 is located at the top of the shell, and the molten metal enters the shell cavity through the top riser 5. Since the core 2 has a through hole 4 in the middle, the molten metal will directly enter the bottom chamber of the core 2 inside the shell through the through hole 4, continuously filling the shell from the bottom upwards during the pouring process. The through-hole 4 in the middle of the core 2 not only allows molten metal to enter the bottom cavity of the shell, but also acts as a riser 5 for the bottom cavity of the core 2. Since the molten metal fills the entire shell from bottom to top, when molten metal begins to enter the through-hole 4 in the middle of the core 2, a U-shaped tube structure is formed because the through-hole 4 is connected to the bottom of the blade-shaped hole 3. As the molten metal level in the through-hole 4 rises, the molten metal level in the blade-shaped hole 3 also rises. The molten metal in the blade-shaped hole 3 originates from the molten metal in the bottom cavity of the shell 2. As the molten metal level rises in the blade-shaped orifice 3, the high-temperature molten metal in the through-hole 4 continuously replenishes the bottom chamber, providing feeding to the bottom chamber of the shell 2. Simultaneously, the molten metal in the through-hole 4 feeds downwards into the bottom chamber, with the feeding direction aligned with gravity. Compared to the traditional method of using a riser 5 at the bottom of the shell for feeding, this invention significantly improves the feeding effect on the bottom chamber of the shell's inner cavity, reducing the probability of blade root loosening defects in the vortex generator. Furthermore, since the bottom of the core 2 within the shell's inner cavity no longer requires a bottom riser 5 for feeding, therefore… Only one riser 5 needs to be retained at the top. The gating system can eliminate the sprue that feeds the molten metal from the bottom riser 5. Since the bottom sprue needs to feed the molten metal into the inner cavity of the mold shell from the bottom, the sprue needs to have a certain length. Eliminating the bottom sprue can reduce the heat loss of the molten metal during the flow of the sprue, which can also reduce the pouring temperature of the molten metal. This is beneficial to reduce the degree of interfacial reaction between the core 2 and the mother alloy, and the surface quality of the throat is improved. At the same time, the ceramic core 2 becomes smaller after being opened, which makes it more convenient to remove the core in the later stage.

[0032] like Figure 4 As shown, the through hole 4 has a circular cross-section, and the axis of the through hole 4 coincides with the axis of the wax model 1.

[0033] In this embodiment, the through hole 4 of the core 2 has a circular cross-section, and the axis of the through hole 4 coincides with the axis of the wax mold 1. After the shell is formed, the through hole 4 is located at the center of the bottom cavity to ensure uniform shrinkage of the bottom cavity.

[0034] A method for casting a vortex generator, applicable to a vortex generator blank with a through hole 4 in the core 2, the casting method includes the following steps:

[0035] Step 1: The wax mold 1 and the core 2 are formed into a whole blank;

[0036] Specifically, the core 2 is processed and formed separately. When the wax mold 1 is pressed, the core 2 is placed in the pressing mold and pressed as a whole to form the vortex blank.

[0037] Step 2: Apply slurry and sand to the blank, and melt part of the wax mold 1 by high-temperature heating to form a shell with the core 2 inside;

[0038] Specifically, the formed vortex blank is immersed in slurry so that there are no dead corners on the surface of the blank. The sand is adhered to the surface of the blank through the slurry. Finally, the whole is heated at high temperature to solidify the sand into a shell. The wax mold 1 melts during the high temperature heating process, so that a cavity is formed inside the shell. The core 2 is suspended horizontally in the inner cavity of the shell.

[0039] Step 3, install the mold shell and gating system, and send molten metal into the inner cavity of the mold shell through the riser 5 at the top of the mold shell through the gating system. The molten metal enters the bottom of the mold shell through the through hole 4 in the middle of the core 2, and fills the mold shell from the bottom to the top.

[0040] Specifically, several finished mold shells are arranged according to the shape of the gating system and installed in the gating system. Then, high-temperature molten metal is poured into the mold shells through the gating system until the molten metal fills the entire mold shell.

[0041] Step 4: After the molten metal cools down, remove the surface shell and the internal core 2;

[0042] Specifically, after the molten metal cools and solidifies, the shell on the surface of the vortex generator is removed by vibration shell removal or high-pressure water shell removal machine. Finally, the core 2 is washed with alkaline solution under high temperature and high pressure to dissolve and fall off. At this time, the vortex generator is fully formed.

[0043] Step 5: Machining removes excess metal from the center of the formed vortex generator;

[0044] Specifically, since the core 2 has a through hole 4 in the middle, when the molten metal in the inner cavity of the shell is cooled and formed, the molten metal in the through hole 4 will also be cooled and formed. This will result in an excess part in the middle of the vortex generator. Finally, the excess metal in the center of the vortex generator needs to be removed by machining and drilling to finally form the vortex generator.

[0045] The yield rate of vortex generators formed using the above-mentioned vortex generator blanks and casting methods is significantly improved.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An eddy current generator blank, characterized in that: The vortex blank includes a wax mold (1) and a core (2) in the middle of the wax mold (1), the core (2) dividing the wax mold (1) into upper and lower parts; The core (2) has several vertically connected blade grooves (3) for forming blades. The blade grooves (3) are evenly spaced around the axial circumference of the wax mold (1) on the surface of the core (2). The core (2) has a through hole (4) in the middle for connecting the upper and lower parts of the wax mold (1); A riser (5) is formed only on the top of the wax mold (1).

2. The eddy current generator blank according to claim 1, characterized in that: The through hole (4) has a circular cross-section, and the axis of the through hole (4) coincides with the axis of the wax mold (1).

3. A method for casting a vortex generator, applicable to a vortex generator blank as described in any one of claims 1-2, characterized in that, The casting method includes the following steps: Step 1: The wax model (1) and the core (2) are formed into a whole blank; Step 2: The blank is coated with slurry and sand, and the wax mold (1) is melted by high temperature heating to form a shell with a core (2) inside; Step 3: Install the mold shell and the gating system. The molten metal is fed into the inner cavity of the mold shell through the riser (5) at the top of the mold shell. The molten metal enters the bottom of the mold shell through the through hole (4) in the middle of the core (2) and fills the mold shell from the bottom up. Step 4: After the molten metal cools down, remove the surface shell and the internal core (2). Step 5: Remove excess metal from the center of the formed vortex generator by machining.

4. The vortex casting method according to claim 3, characterized in that, The blank forming method in step 1 is as follows: the core (2) is processed and formed separately. When the wax mold (1) is pressed and formed, the core (2) is placed in the pressing mold and pressed and formed as a whole, and finally the vortex blank is formed.

5. The vortex casting method according to claim 3, characterized in that, The molding method of the shell in step 2 is as follows: the molded vortex blank is immersed in the slurry so that there are no dead corners on the surface of the blank. The sand is adhered to the surface of the blank through the slurry. Finally, the whole is heated at high temperature to solidify the sand into a block to form a shell. The wax mold (1) melts during the high temperature heating process, so that a cavity is formed inside the shell. The core (2) is suspended horizontally in the inner cavity of the shell.

6. The vortex casting method according to claim 3, characterized in that, The installation method of the shell in step 3 is as follows: several processed shells are arranged and installed in the gating system according to the shape of the gating system.

7. The vortex casting method according to claim 3, characterized in that, The method for removing the shell and core in step 4 is as follows: after the molten metal cools and solidifies, the shell on the surface of the vortex generator is removed by vibration shell removal or high-pressure water shell removal machine. Finally, the core (2) is washed with alkaline solution under high temperature and high pressure environment to dissolve and fall off the core (2).

8. The vortex casting method according to claim 3, characterized in that, The method for removing excess metal in step 5 is as follows: excess metal in the center of the eddy current generator is removed by machining and drilling.

Images