Anti-gravity investment molding apparatus and method

Abstract

The application provides an anti-gravity investment casting molding device and method. The anti-gravity investment casting molding device comprises an outer box body, an inner cylinder and a box cover. The outer box body is a barrel-shaped structure with an open end. The bottom of the outer box body comprises a conical hole and a groove. The conical hole is located at the center. The inner cylinder is a sleeve structure with open ends. One end of the inner cylinder is buckled to the groove. A ceramic mold shell is arranged in the space surrounded by the inner cylinder and the conical hole. The outer diameter of the inner cylinder is determined according to the ceramic mold shell to cooperate with different grooves for fixation. The box cover is buckled to the open end of the outer box body and is attached to the top of the inner cylinder. A refractory layer is arranged between the box cover and the ceramic mold shell. The anti-gravity investment casting molding method is applied to the anti-gravity investment casting molding device. The inner cylinder cooperates with the groove of the outer box body, improving the applicability and simplifying the operation. The compression amount of the refractory cotton is adjusted to control the compression force, effectively avoiding the damage of the ceramic mold shell and the spraying of the metal liquid, and the safety factor is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic shell for casting, and particularly relates to a device and method for anti-gravity precision casting molding which are widely applicable, simple to operate and high in safety factor. BACKGROUND

[0002] Anti-gravity investment casting is an advanced casting method in which molten metal fills the mold cavity from bottom to top along the riser under the action of gas pressure difference and solidifies under pressure, and has significant advantages over traditional gravity casting in terms of mold filling, feeding and inclusion control. The ceramic shell for investment casting generally needs to be preheated to above 600 DEG C in a shell preheating furnace, and after a certain time of heat preservation, it is transferred to a casting room or the like for pouring. In this process, the molding device plays a role in fixing the ceramic shell and facilitating the transfer. Since the ceramic shell needs to withstand the filling and solidification pressure exerted by the gas during the anti-gravity casting process, higher requirements are put forward for the stability of the ceramic shell. If the stability measures for the ceramic shell are not appropriate, displacement of the ceramic shell or damage of the ceramic shell due to excessive stress during the stability process will occur during the mold filling and solidification process of the molten metal, which will cause high-temperature molten metal to splash and cause serious personnel and property losses.

[0003] Patent CN 105945258 A uses clay sand to fix the sprue cup, uses dry sand to fill the sand box and uses a cover plate to press the sand tightly, which plays a good role in stabilizing the ceramic shell during the mold filling and solidification process of the metal liquid. However, this method relies on dry sand to fix the ceramic shell and can only realize sand-embedded molding. Patent CN 110328351 A improves the flange sprue cup and proposes a process method for anti-gravity pouring of investment castings without water glass sand molding, but this molding process is still limited to sand-embedded molding filled with dry sand. Using the sand-embedded molding method, due to the poor thermal conductivity of the ceramic shell and the sand filling material, in order to reduce the preheating time of the shell and facilitate the cooling of the casting, the maximum distance from the ceramic shell to the sand box is generally not more than 40 mm, so the above-mentioned invention still cannot meet the molding needs of ceramic shells of different sizes, and different specifications of sand boxes need to be frequently replaced during the production process, which is not conducive to the realization of automatic transfer of sand boxes under high-temperature conditions. In addition, for large-size castings, the sand-embedded molding method is prone to cause difficulties in solidification, feeding and grain organization of the casting, thereby affecting the quality of the casting. How to realize a ceramic shell molding method which is widely applicable, simple to operate and high in safety factor has become a problem urgently to be solved in the anti-gravity investment casting industry.

[0004] Therefore, the existing anti-gravity investment casting mold box has the problems of multiple specifications, frequent replacement, and being not conducive to the mechanization of hot sand box transfer; the molding method is limited to sand embedding molding, and the application of the anti-gravity investment casting technology on large-size castings is limited. Therefore, a molding device for anti-gravity investment casting is developed, which can be applied to ceramic shells of different sizes, and solves the problems of fixing and locking the ceramic shell of the anti-gravity investment casting, and realizes various molding methods (such as sand filling, cotton wrapping, and single shell, etc.) of the ceramic shell. The molding device has important significance for the automatic upgrading of the anti-gravity investment casting technology and the application and promotion of the anti-gravity investment casting technology on large-size castings. SUMMARY

[0005] A main object of the present application is to overcome at least one of the above-mentioned problems of the prior art, and to provide an anti-gravity investment casting molding device and method which have wide applicability, simple operation, and high safety factor.

[0006] To achieve the above-mentioned objects, the present application adopts the following technical solutions.

[0007] According to one aspect of the present application, an anti-gravity investment casting molding device is provided, comprising:

[0008] An outer box body, which is a barrel-shaped structure with one end open, comprises a conical hole and grooves at the bottom, the conical hole is located at the center, and the grooves are two or more than two and are arranged in turn around the outside of the conical hole;

[0009] An inner cylinder, which is a sleeve structure with both ends open, is clamped to the grooves at one end, the ceramic shell is arranged in the space surrounded by the inner cylinder and the conical hole, and the outer diameter size of the inner cylinder is determined according to the ceramic shell to fix different grooves.

[0010] A box cover, which is clamped to the open position of the outer box body and fits the top of the inner cylinder, is arranged between the ceramic shell and the refractory layer.

[0011] According to one specific embodiment of the present application, a guide column is arranged around the inside of the open position of the outer box body, and a guide groove is arranged on the box cover, and the guide column is matched with the guide groove.

[0012] According to one specific embodiment of the present application, a plurality of air permeable holes are arranged in an array on the box cover.

[0013] According to one specific embodiment of the present application, the refractory layer comprises refractory pads and refractory cotton, the refractory pads are close to the ceramic shell, and the refractory cotton is close to the box cover and has compressibility.

[0014] According to one specific embodiment of the present application, the inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material; or,

[0015] The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material, and the exposed surface of the ceramic mold shell is wrapped with thermal insulation cotton; or,

[0016] The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material, and the exposed surface of the ceramic mold shell is wrapped with thermal insulation cotton; or,

[0017] The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material, and the exposed surface of the ceramic mold shell is wrapped with thermal insulation cotton; or,

[0018] Step one, the ceramic mold shell is inverted and buckled in the center circular hole of the outer box body bottom plate;

[0019] Step two, according to the size of the ceramic mold shell, select the appropriate inner cylinder;

[0020] Step three, the inner cylinder is buckled in the corresponding size groove;

[0021] Step four, the outer side of the ceramic mold shell is laid with refractory material;

[0022] Step five, the inner cylinder is filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material; or,

[0023] Step six, the box cover is buckled in the outer box body and pressed on the refractory layer;

[0024] Step seven, the center position of the box cover is applied with a pressing force to compress and fix the refractory layer, the ceramic mold shell and the outer box body.

[0025] According to one specific embodiment of the present application, the step four includes:

[0026] The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material; or,

[0027] The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material, and the exposed surface of the ceramic mold shell is wrapped with thermal insulation cotton; or,

[0028] The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic mold shell is embedded in the refractory material, and the exposed surface of the ceramic mold shell is wrapped with thermal insulation cotton; or,

[0029] According to one specific embodiment of the present application, the step five includes:

[0030] Put the refractory pad on the inner ceramic shell, and the height should be lower than the inner cylinder after placing; Put the compressible refractory cotton on the refractory pad, and the height should be higher than the inner cylinder after placing. According to one specific embodiment of the present application, the step six includes:

[0031] After aligning the guide slot of the box cover with the guide column of the outer box body, place the outer box body in the outer box body, and press on the compressible refractory cotton and the inner cylinder.

[0032] According to one specific embodiment of the present application, the compressive force applied at the center of the box cover in step seven will be shared by the inner cylinder when the part of the refractory cotton higher than the inner cylinder is compressed to be flush with the inner cylinder, preventing damage to the ceramic shell due to excessive compressive force or impact during compression, causing high-temperature metal liquid to be ejected.

[0033] From the above technical solution, the advantages and positive effects of the anti-gravity investment casting molding device and method of the present application are that:

[0034] The inner cylinder cooperates with the groove of the outer box body, improving the applicability and being simple to operate; the compressible refractory cotton is used to isolate the box cover and the ceramic shell, and the compressive force is controlled by adjusting the compression amount of the refractory cotton, effectively preventing the ceramic shell from being damaged and causing metal liquid to be ejected, and the safety factor is high. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a cross-sectional structure schematic diagram of the first embodiment of the anti-gravity investment casting molding device of the present application;

[0036] Figure 2 is a three-dimensional structure schematic diagram of the outer box body in the anti-gravity investment casting molding device of the present application;

[0037] Figure 3 is a three-dimensional structure schematic diagram of the box cover in the anti-gravity investment casting molding device of the present application;

[0038] Figure 4 is a cross-sectional structure schematic diagram of the second embodiment of the anti-gravity investment casting molding device of the present application;

[0039] Figure 5 is a cross-sectional structure schematic diagram of the third embodiment of the anti-gravity investment casting molding device of the present application.

[0040] FIG. NO. EXPLANATION:

[0041] 1: outer box body, 11: guide column, 12: hoisting hole, 13: groove, 14: conical hole; 2: inner cylinder; 3: box cover, 31: guide slot, 32: air hole; 4: ceramic shell; 5: refractory pad; 6: refractory cotton; 7: molding refractory material; 8: insulation cotton. DETAILED DESCRIPTION

[0042] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations can, however, be implemented in many different forms and should not be considered limited to the implementations set forth in this disclosure; rather, these implementations are provided as example ( s ) ( laying out currently preferred embodiments of the application ) to provide an enabling description for the exercise of the underlying inventive concepts over a full scope of possibilities. Like reference numerals are used to refer to like elements throughout and detailed descriptions of the like elements will not be repeated here.

[0043] In the following description of the various examples of the application, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example structures, systems, and steps in which aspects of the application can be practiced. It is to be understood that other specific arrangements of parts, structures, example devices, systems, and steps can be utilized and that structural and functional modifications can be made without departing from the scope of the present application. Also, while the terms "top," "bottom," "front," "back," "side," and the like can be used in this specification to describe various example features and elements of the application, these terms are used herein as a shorthand notations for ease of description only. Any of the terms thus have only a relative meaning and should not be construed as limiting the scope of the application.

[0044] As Figures 1 to 5 shown, the anti-gravity investment casting molding device of the present application comprises:

[0045] An outer box body 1, which is a barrel-shaped structure with one end open, comprises a tapered circular hole 14 and grooves 13 at the bottom. The tapered circular hole 14 is located at the center, and the grooves 13 are more than two and are arranged in sequence around the outside of the tapered circular hole 14.

[0046] An inner cylinder 2, which is a sleeve structure with both ends open, is buckled to the grooves 13. The ceramic mold shell 4 is arranged in the space surrounded by the inner cylinder 2 and the tapered circular hole 14. The outer diameter size of the inner cylinder 2 is determined according to the ceramic mold shell 4 to match different grooves 13 for fixation.

[0047] A box cover 3 is buckled to the open position of the outer box body 1 and is attached to the top of the inner cylinder 2. A refractory layer is arranged between the box cover 3 and the ceramic mold shell 4 to support and fix the ceramic mold shell 4.

[0048] According to a specific embodiment of the present application, a guide column 11 is arranged around the inside of the open position of the outer box body 1. A guide groove 31 is arranged on the box cover 3, and the guide column 11 is matched with the guide groove 31.

[0049] According to a specific embodiment of the present application, a lifting hole 12 is arranged on the sidewall of the outer box body 1 at the lower part of the guide column 11.

[0050] According to one embodiment of the present application, the box cover 3 is provided with a plurality of air holes 32 arranged in an array.

[0051] According to one embodiment of the present application, the refractory layer comprises a refractory pad 5 close to the ceramic shell 4 and a refractory cotton 6 close to the box cover 3.

[0052] According to one embodiment of the present application, the inner cylinder 2 and the outer box 1 are filled with a molding refractory material 7, and the lower part of the ceramic shell 4 is embedded in the molding refractory material 7; or,

[0053] The inner cylinder 2 and the outer box 1 are filled with a molding refractory material 7, and the lower part of the ceramic shell 4 is embedded in the molding refractory material 7, and the exposed surface of the ceramic shell 4 is wrapped with a heat insulation cotton 8; or,

[0054] The inner cylinder 2 and the ceramic shell 4 are filled with a molding refractory material 7.

[0055] According to another aspect of the present application, a counter-gravity investment casting molding method is provided, which is applied to the counter-gravity investment casting molding device as described above, and comprises the following steps:

[0056] Step one, the ceramic shell 4 is inverted and buckled in the center hole of the bottom plate of the outer box 1;

[0057] Step two, according to the size of the ceramic shell 4, a suitable inner cylinder 2 is selected;

[0058] Step three, the inner cylinder 2 is buckled in the corresponding size groove 13;

[0059] Step four, the outer side of the ceramic shell 4 is provided with a refractory cloth;

[0060] Step five, a refractory layer is provided on the ceramic shell 4 in the inner cylinder 2;

[0061] Step six, the box cover 3 is buckled in the outer box 1 and pressed on the refractory layer;

[0062] Step seven, a pressing force is applied to the center position of the box cover 3 to press and fix the refractory layer, the ceramic shell 4 and the outer box 1.

[0063] According to one embodiment of the present application, the step four comprises:

[0064] The inner cylinder 2 and the outer box 1 are filled with a molding refractory material 7, and the lower part of the ceramic shell 4 is embedded in the refractory material; or,

[0065] Filling molding refractory 7 between the inner cylinder 2 and the outer box 1, burying the lower part of the ceramic mold shell 4 in the molding refractory 7, and wrapping the exposed surface of the ceramic mold shell 4 with thermal cotton 8; or,

[0066] Filling molding refractory 7 between the inner cylinder 2 and the ceramic mold shell 4.

[0067] According to one embodiment of the present application, the step five comprises:

[0068] Placing a refractory pad 5 on the ceramic mold shell 4 in the inner cylinder;

[0069] Placing refractory cotton 6 on the refractory pad 5.

[0070] According to one embodiment of the present application, the step six comprises:

[0071] After aligning the guide slot of the box cover 3 with the guide column 11 of the outer box 1, placing the outer box 1 in the outer box 1, and pressing the compressible refractory cotton 6 and the inner cylinder 2.

[0072] From the above technical solution, the advantages and positive effects of the anti-gravity investment casting molding device and method of the present application are:

[0073] The inner cylinder 2 cooperates with the groove 13 of the outer box 1, improving the applicability and being simple to operate, and the refractory layer isolation box cover 3 and the ceramic mold shell 4 have a high safety factor.

[0074] The present application is suitable for different sizes of ceramic mold shell 4, and the size specification of the outer box 1 is uniform, which creates a convenient condition for the transfer automation of the outer box 1; at the same time, the problems of fixing and compressing the anti-gravity investment casting ceramic mold shell are solved, and a molding process of the ceramic mold shell is provided, which can flexibly adjust the size of the ceramic mold shell compression force and protect the ceramic mold shell in the case of excessive compression force, can realize the molding methods of anti-gravity investment casting sand burying, single shell and cotton wrapping at the same time, and eliminates the restriction of anti-gravity investment casting on large size casting forming, which has significant economic value in the future.

[0075] Figures 1 to 5The specific structure of three embodiments of the present application is shown. In the anti-gravity investment casting process, the ceramic shell 4 has high requirements for the precision of the transfer and assembly position, and bears a certain pressure during the metal liquid filling and solidification process. Therefore, the sand box of the anti-gravity investment casting not only needs to be easily automated, but also needs to fix and lock the ceramic shell 4, so that it does not move under the condition of bearing the filling and feeding pressure of the metal liquid, so as to prevent the high-temperature metal liquid from leaking. The existing anti-gravity investment casting sand box cannot be unified in size and is severely dependent on the way of filling and solidifying dry sand refractory material to fix the ceramic shell 4, which makes it difficult to realize the automatic transfer of the sand box and seriously affects the heat dissipation of large-size castings. Therefore, there is an urgent need for a sand box suitable for ceramic shell of different sizes and a ceramic shell molding method limited to buried sand molding.

[0076] The device provided by the present application comprises an outer box body 1, an inner cylinder 2, and a box cover 3. The ceramic shell molding method provided by the present application is as follows: the ceramic shell 4 is inverted and buckled in the center hole of the bottom plate of the outer box body; according to the size of the ceramic shell 4, an appropriate inner cylinder 2 is selected; the inner cylinder 2 is buckled in the corresponding size groove 13; a certain height of molding refractory material 7 is filled into the gap between the outer box body 1 and the inner cylinder 2 and the bottom of the outer box body 1; a refractory pad 5 of appropriate size is placed on the ceramic shell 4 in the inner cylinder 2; a certain thickness of refractory cotton 6 is placed on the refractory pad 5; after the guide groove 31 of the box cover 3 is aligned with the guide column 11 of the outer box body 1, the outer box body 1 is placed in the outer box body 1 and pressed on the compressible refractory cotton 6 and the inner cylinder 2, and the ceramic shell 4 molding is completed.

[0077] Figure 1 is a sectional view of a first embodiment of an anti-gravity investment casting sand box and a ceramic shell molding method provided by the present application. As can be seen from the figure, the sand box comprises an outer box body 1, an inner cylinder 2, and a box cover 3. The ceramic shell molding method is as follows: the ceramic shell 4 is inverted and buckled in the tapered hole 14 in the center of the bottom plate of the outer box body 1; according to the size of the ceramic shell 4, an appropriate size inner cylinder 2 is selected; the inner cylinder 2 is buckled in the corresponding size groove 13 at the bottom of the outer box body 1; the gap between the outer box body 1 and the inner cylinder 2 and the gap between the inner cylinder 2 and the ceramic shell 4 are respectively filled with molding refractory material; the refractory pad 5 is placed on the ceramic shell 4; the compressible refractory cotton 6 is placed on the refractory pad 5; after the guide groove 31 of the box cover 3 is aligned with the guide column 11 of the outer box body, the outer box body 1 is placed in the outer box body 1 and pressed on the compressible refractory cotton 6 and the inner cylinder 2, and the ceramic shell single shell molding is completed.

[0078] The outer box body 1 is characterized in that the side wall is provided with guide columns 11 and lifting holes 12, the bottom is provided with grooves 13 of different diameters, the center of the bottom is provided with a tapered circular hole 14, the number of guide columns and lifting holes is 4, and the size of the grooves is 5; the inner cylinder 2 is characterized in that it is matched with the first groove of the bottom of the outer box body; the box cover 3 is characterized in that the side surface is provided with four guide grooves corresponding to the guide columns of the outer box body, and the front surface is provided with air holes; the refractory pad 5 is characterized in that the main material is silicon oxide, and hot-pressing injection molding is adopted.

[0079] The compressible refractory cotton 6 is characterized in that the thickness is 10 mm, wherein the height above the inner cylinder is 6 mm; the molding refractory material 7 is characterized in that it is an aluminum oxide hollow sphere, and is filled between the outer box body 1 and the inner cylinder 2 to a height slightly lower than the lifting hole 12, and is filled between the inner cylinder 2 and the ceramic mold shell 4 to a height of 30 mm.

[0080] The box cover 3 is provided with guide grooves 31 on the side surface corresponding to the guide columns of the outer box body, and is provided with air holes 32 on the front surface. The guide grooves 31 can prevent the box cover 3 from deflecting during compression, and the air holes 32 are beneficial to the extraction of gas in the sand box. The ceramic mold shell 4 is provided with a tapered protrusion on the sprue cup, which is matched with the tapered circular hole 14 in the center of the bottom plate of the outer box body 1. The refractory pad 5 has parallel upper and lower end surfaces, and the material can be a mixture of one or more of aluminum oxide, silicon oxide and magnesium oxide. The refractory cotton 6 can be compressed, the thickness is not less than 5 mm, and the total height of the ceramic mold shell 4, the refractory pad 5 and the refractory cotton 6 after assembly should be higher than the inner cylinder by not less than 3 mm. The outer box body 1 and the inner cylinder 2 can be filled with molding refractory material 7 of different heights as needed, and the molding refractory material 7 can be quartz sand, coal gangue or aluminum oxide hollow sphere, which can prevent the metal liquid from spattering and overflowing, damaging equipment and causing personnel safety accidents. The compression mechanism of the sand box acts on the center position of the box cover 3, and when the refractory cotton 6 above the inner cylinder 2 is compressed to be flush with the inner cylinder 2 under the action of the compression force, the compression force will be shared by the inner cylinder 2, which can prevent the ceramic mold shell 4 from being damaged due to excessive compression force and causing high-temperature metal liquid spattering.

[0081] Figure 4A cross-sectional view of a second embodiment of the anti-gravity investment casting sand box and ceramic shell molding method provided by the present application. The sand box of the embodiment includes an outer box body 1, an inner cylinder 2, a box cover 3, and is the same as the above embodiment, and the same features will not be described here. As can be seen from the figure, the outer surface of the ceramic shell 4 is wrapped with a layer of heat insulation cotton; the ceramic shell molding method is: wrapping the ceramic shell 4 with a layer of 10mm thick heat insulation cotton 8, and then inverting and fitting into the conical circular hole 14 in the center of the bottom plate of the outer box body 1; according to the size of the ceramic shell 4, selecting an inner cylinder 2 with a suitable size; fitting the inner cylinder 2 into the corresponding size groove 13 of the outer box body 1; filling the gap between the outer box body 1 and the inner cylinder 2 and the gap between the inner cylinder 2 and the ceramic shell 4 with molding refractory material 7 respectively; placing a refractory pad 5 on the ceramic shell 4; placing compressible refractory cotton 6 on the refractory pad 5; after aligning the guide groove 31 of the box cover 3 with the guide column 11 of the outer box body, placing the outer box body 1 into the outer box body 1, pressing on the compressible refractory cotton 6 and the inner cylinder 2, and completing the ceramic shell cotton wrapping molding.

[0082] Figure 5 A cross-sectional view of a third embodiment of the variable-diameter anti-gravity investment casting sand box and ceramic shell molding method provided by the present application. The outer box body 1 and the box cover 3 of the sand box of the embodiment are the same as the above embodiment, and the same features will not be described here. As can be seen from the figure, the molding refractory material 7 fills the gap between the inner cylinder 2 and the ceramic shell 4. The ceramic shell molding method is: inverting and fitting the ceramic shell 4 into the conical circular hole 14 in the center of the bottom plate of the outer box body 1; according to the size of the ceramic shell 4, selecting an inner cylinder 2 with a suitable size; fitting the inner cylinder 2 into the corresponding size groove 13 of the outer box body 1; placing a refractory pad 5 on the ceramic shell 4; placing compressible refractory cotton 6 on the refractory pad 5; filling the gap between the inner cylinder 2 and the ceramic shell 4 with molding refractory material 7 respectively until the height of the inner cylinder 2 is flush; after aligning the guide groove 31 of the box cover 3 with the guide column 11 of the outer box body 1, placing the outer box body 1 into the outer box body 1, pressing on the compressible refractory cotton 6 and the inner cylinder 2, and completing the ceramic shell cotton wrapping molding. The ceramic shell sand embedding molding is completed.

[0083] The inner cylinder 2 is characterized in that the size specification matches the second groove 13 on the bottom surface of the outer box body 1 to ensure that the sand filling thickness is about 40mm. The molding refractory material 7 is characterized in that the material is quartz sand.

[0084] The size of the ceramic shell 4 varies according to the actual product size, and the present application only needs to replace the inner cylinder 2 which is simple in structure, low in cost and easy to operate, to meet the production needs of ceramic shells 4 of different sizes. Moreover, the overall structure does not need to be replaced in this process, and the outer contour size of the outer box body 1 remains consistent, thereby reducing the difficulty of realizing the overall mechanized transfer scheme under high temperature conditions and solving the problem of not being conducive to realizing automatic transfer under high temperature conditions.

[0085] The pressing force acting on the central axis is applied on the box cover 3, and the guide column 11 and the guide groove 31 prevent the pressing force from tilting, so that the pressing force can effectively act on the central axis and the structure of the ceramic shell 4 is stable.

[0086] The required pressing force corresponding to a certain compression amount of the same refractory cotton 6 is relatively fixed. The present application controls the compression amount of the refractory cotton 6 by controlling the relationship between the total height of the superimposed ceramic shell 4, refractory cushion 5 and refractory cotton 6 and the height of the inner cylinder 2, and then controls the pressing force. For example, the total height of the superimposed ceramic shell 4, refractory cushion 5 and refractory cotton 6 is 500 mm, and the height of the inner cylinder 2 is 495 mm, and the thickness of the refractory cotton 6 used is 10 mm, so that the height of the refractory cotton 6 above the inner cylinder 2 is 5 mm. During the pressing process of the box cover 3, the refractory cotton 6 is compressed before the inner cylinder 2, and when the compression amount reaches 5 mm, the inner cylinder 2 and the refractory cotton 6 are compressed at the same time. Since the material of the inner cylinder 2 is heat-resistant steel, the compression amount under stress can be ignored compared with the refractory cotton 6. Therefore, the pressing force required for the 5 mm compression amount above the refractory cotton 6 will be shared by the inner cylinder 2, so as to control the pressing force. In addition, the purpose of controlling the pressing force required by the ceramic shell 4 is to stabilize the ceramic shell 4, so that the implementation means has operability in actual production.

[0087] Those skilled in the art to which the present application pertains should understand that the specific structures and processes shown in the above detailed description part are only exemplary and not limiting. Moreover, those skilled in the art can combine the various technical features shown above in various possible ways to form new technical solutions, or make other modifications, which all belong to the scope of the present application.

Claims

1. An anti-gravity investment molding apparatus, characterized by comprising: It comprises: An outer box body in the shape of a barrel with one end open, the bottom of the outer box body comprising a conical hole in the center and more than two grooves arranged in sequence around the outside of the conical hole; An inner cylinder in the shape of a sleeve with both ends open, one end of the inner cylinder being fastened to the groove, a ceramic shell being arranged in the space enclosed by the inner cylinder and the conical hole, the outer diameter of the inner cylinder being determined according to the ceramic shell to fit different grooves; A box cover fastened to the open position of the outer box body and fitted to the top of the inner cylinder, a refractory layer being arranged between the box cover and the ceramic shell, the refractory layer comprising refractory blocks close to the ceramic shell and compressible refractory cotton close to the box cover.

2. The anti-gravity investment molding apparatus according to claim 1, characterized by: A guide column is arranged around the inside of the open position of the outer box body, and a guide groove is arranged on the box cover, the guide column being matched with the guide groove.

3. The anti-gravity investment molding apparatus according to claim 2, characterized by: Ventilation holes are arranged in an array on the box cover.

4. The anti-gravity investment casting molding device according to claim 1, characterized in that: The inner cylinder and the outer box body are filled with molding refractory material, and the lower part of the ceramic shell is embedded in the refractory material; or The inner cylinder and the outer box body are filled with molding refractory material, the lower part of the ceramic shell is embedded in the refractory material, and the exposed surface of the ceramic shell is wrapped with thermal insulation cotton; or The inner cylinder and the ceramic shell are filled with molding refractory material.

5. A method of countergravity investment casting molding, characterized by: The anti-gravity investment casting molding device according to any one of claims 1-4 comprises the following steps: Step one: Invert the ceramic shell in the center hole of the outer box body bottom plate; Step two: Select the appropriate inner cylinder according to the size of the ceramic shell; Step three: Fasten the inner cylinder in the corresponding size groove; Step four: Lay the refractory cloth on the outside of the ceramic shell; Step five: Set the refractory layer on the ceramic shell in the inner cylinder; Step six: Fasten the box cover in the outer box body and press on the refractory layer; Step seven: Apply pressure to the center position of the box cover to compress and fix the refractory layer, ceramic shell and outer box body.

6. The counter-gravity investment casting molding method according to claim 5, characterized by: In step four, it comprises: Fill the molding refractory material between the inner cylinder and the outer box body, and embed the lower part of the ceramic shell in the refractory material; or Fill the molding refractory material between the inner cylinder and the outer box body, embed the lower part of the ceramic shell in the refractory material, and wrap the exposed surface of the ceramic shell with thermal insulation cotton; or Fill the molding refractory material between the inner cylinder and the ceramic shell.

7. The counter-gravity investment casting molding method according to claim 6, characterized by: In step five, it comprises: Place the refractory blocks on the ceramic shell in the inner cylinder, and the height after placement should be lower than the inner cylinder; place the compressible refractory cotton on the refractory blocks, and the height after placement should be higher than the inner cylinder.

8. The counter-gravity investment casting molding method according to claim 5, characterized by: In step six, it comprises: After aligning the guide groove of the box cover with the guide column of the outer box body, place the outer box body in the outer box body, and press on the compressible refractory cotton and the inner cylinder.

9. The counter-gravity investment casting molding method according to claim 5, characterized by: The pressing force applied at the center of the box cover in step seven will be shared by the inner cylinder when the refractory cotton is compressed to the level of the inner cylinder, preventing the ceramic mold shell from being damaged due to excessive pressing force or impact during the pressing process, which may cause the high-temperature metal liquid to be ejected.

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