A manufacturing process for rapid crust formation of a core

Abstract

The present invention provides a manufacturing process for rapid shell formation of cores, which relates to the technical field of core shooting. The process includes: starting an air compressor so that the compressed air output therefrom enters a first output pipeline and a second output pipeline respectively; using a first sand box to output sand grains to the first output pipeline and using a second sand box to output sand grains to the second output pipeline; after the gas output from the first output pipeline is mixed with the sand grains output from the first sand box, it enters a first sand shooting cylinder; after the gas output from the second output pipeline carries the sand grains output from the second sand box, it enters a second sand shooting cylinder; the first sand shooting cylinder and the second sand shooting cylinder respectively shoot sand into a mold through a first annular sand hole and a second circular sand hole on the mold; heating the sand grains in the mold by a heating device outside the mold to cause them to form a shell. The embodiment of the present invention provides a manufacturing process for rapid shell formation of cores, which can improve the speed of shell formation of cores.

Description

Technical Field

[0001] The present invention relates to the technical field of core shooting, and particularly to a manufacturing process for rapid shell formation of cores. Background Art

[0002] Core shooting technology is a process of rapidly forming sand grains in a mold through a core shooter.

[0003] In related technologies, sand grains are ejected into a mold through a core shooting device, so that the mold is quickly filled with sand grains. The sand grains are mixed with a thermosetting resin. After heating the sand grains, a core formed by shell formation of the sand grains is obtained. However, since it takes a certain amount of time for the sand grains to be heated and cured, the speed of shell formation is limited. Summary of the Invention

[0004] An embodiment of the present invention provides a manufacturing process for rapid shell formation of cores, which can improve the speed of shell formation of cores. The technical solution of the present invention is as follows:

[0005] A manufacturing process for rapid shell formation of cores includes:

[0006] Start an air compressor so that the compressed air output by it enters a first output pipeline and a second output pipeline respectively; wherein, the cross-sectional area of the first output pipeline gradually decreases along the gas flow direction, so as to increase the pressure and temperature of the compressed air inside it;

[0007] Use a first sand box to output sand grains to the first output pipeline, and use a second sand box to output sand grains to the second output pipeline;

[0008] The gas output by the first output pipeline is mixed with the sand grains output by the first sand box and then enters a first sand shooting cylinder; wherein, the first sand shooting cylinder includes an inner cylinder and an outer cylinder both in a cylindrical shape, and the space formed between the inner cylinder and the outer cylinder is communicated with the first output pipeline. One end of the first sand shooting cylinder is surrounded by the outer cylinder and the inner cylinder to form an annular outlet for ejecting an annular sand beam;

[0009] The gas output by the second output pipeline carries the sand grains output by the second sand box and then enters a second sand shooting cylinder; wherein, the second sand shooting cylinder passes through the inner cylinder, and the outlet of the second sand shooting cylinder is circular to eject a circular sand column inside the annular sand beam;

[0010] The first sand shooting cylinder and the second sand shooting cylinder respectively shoot sand into the mold through a first sand hole in a ring shape and a second sand hole in a circular shape on the mold;

[0011] Use a heating device outside the mold to heat the sand grains in the mold to make them form a shell.

[0012] Optionally, both the inner cylinder and the outer cylinder include a conical part and a cylindrical part along the axis.

[0013] Optionally, a heating chamber is provided outside the mold, water is filled in the heating chamber, and the heating device includes a microwave device;

[0014] Heating the sand in the mold by using the heating device outside the mold to cause it to crust includes:

[0015] Applying microwaves to the heating chamber by using the microwave device to raise the temperature of the heating chamber, and the heating chamber heats the mold wrapped by it and the sand grains inside to crust.

[0016] Optionally, the mold is provided with exhaust holes, a filter screen is installed on the exhaust holes, the mesh of the filter screen is smaller than the particle size of the sand grains, the exhaust holes are communicated with the heating chamber through an atomization pipeline, a piston device is arranged in the atomization pipeline, the piston device divides the atomization pipeline into two parts, a part of the atomization pipeline communicated with the exhaust holes is a gas phase, a part of the atomization pipeline communicated with the heating chamber is a water phase, and the atomization pipeline is communicated with the heating chamber through an atomization nozzle;

[0017] The gas discharged from the exhaust holes pushes the piston device to spray the water in the atomization pipeline into the heating chamber through the atomization nozzle.

[0018] Optionally, the piston device includes a housing, a first piston and a second piston, the housing includes a first part and a second part which are communicated with each other, the cross-sectional area of the first part is smaller than that of the second part, the first piston is slidably and sealingly installed in the first part, the second piston is slidably and sealingly installed in the second part, and a liquid is filled in the space formed by the first piston, the second piston and the housing.

[0019] Optionally, a pressure relief valve is installed on the atomization pipeline.

[0020] Optionally, baffles are provided at the outlets of the first sand box and the second sand box to adjust the sand discharge amounts of the two.

[0021] Optionally, the sand grains in the first sand box and the second sand box contain phenolic resin.

[0022] Optionally, flow regulating valves are installed on the first output pipeline and the second output pipeline.

[0023] The present invention has at least the following beneficial effects compared with the prior art:

[0024] In this embodiment, by setting the cross-sectional area of the first output pipeline to gradually decrease along the gas flow direction, the compressed air entering the inside of the first output pipeline can be pressurized and heated, and then the sand grains flowing into the first output pipeline can be preheated. After the high-temperature and high-pressure gas output from the first output pipeline carries the preheated sand grains and flows into the first sand shooting cylinder, the annular sand beam shot out by the first sand shooting cylinder is output into the mold and is mainly distributed around the mold. The sand grains output from the second output pipeline enter the second sand shooting cylinder, and the circular sand column shot out by the second sand shooting cylinder fills the middle of the mold. Finally, a sand core with preheated sand grains on the outside and normal sand grains in the middle is obtained in the mold. The sand grains around the mold are heated by the heating device to form a shell. The preheated sand grains can be heated and shelled faster under the action of the heating device, thereby improving the speed of the core shelling. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a schematic structural diagram of a core rapid shelling device provided by an embodiment of the present invention.

[0027] In the figure:

[0028] 1 - Air compressor;

[0029] 11 - First output pipeline;

[0030] 12 - Second output pipeline;

[0031] 2 - First sand box;

[0032] 3 - Second sand box;

[0033] 4 - First sand shooting cylinder;

[0034] 41 - Inner cylinder;

[0035] 42 - Outer cylinder;

[0036] 5 - Second sand shooting cylinder;

[0037] 6 - Heating chamber;

[0038] 7 - Microwave device;

[0039] 8 - Mold;

[0040] 81 - Exhaust hole;

[0041] 9 - Atomization pipeline;

[0042] 91 - Piston device;

[0043] 911 - First piston;

[0044] 912 - Second piston;

[0045] 913 - Housing;

[0046] 92 - Atomizing nozzle;

[0047] 93 - Pressure relief valve. Detailed implementation manners

[0048] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] As Figure 1 shown, the embodiments of the present invention provide a manufacturing process for rapid core shelling, which is realized by a rapid core shelling device and includes:

[0050] Turn on the air compressor 1 so that the compressed air output therefrom enters the first output pipeline 11 and the second output pipeline 12 respectively; wherein, the cross-sectional area of the first output pipeline 11 gradually decreases along the gas flow direction to increase the pressure and temperature of the compressed air therein;

[0051] Use the first sand box 2 to output sand grains to the first output pipeline 11, and use the second sand box 3 to output sand grains to the second output pipeline 12;

[0052] The gas output from the first output pipeline 11 is mixed with the sand grains output from the first sand box 2 and then enters the first sand shooting cylinder 4; wherein, the first sand shooting cylinder 4 includes an inner cylinder 41 and an outer cylinder 42 both in a cylindrical shape, and the space formed between the inner cylinder 41 and the outer cylinder 42 is communicated with the first output pipeline 11. One end of the first sand shooting cylinder 4 is surrounded by the outer cylinder 42 and the inner cylinder 41 to form an annular outlet for ejecting an annular sand beam;

[0053] The gas output from the second output pipeline 12 carries the sand grains output from the second sand box 3 and then enters the second sand shooting cylinder 5; wherein, the second sand shooting cylinder 5 passes through the inner cylinder 41, and the outlet of the second sand shooting cylinder 5 is circular to eject a circular sand column within the annular sand beam;

[0054] The first sand shooting cylinder 4 and the second sand shooting cylinder 5 shoot sand into the mold 8 through the annular first sand hole and the circular second sand hole on the mold 8 respectively;

[0055] The sand grains in the mold 8 are heated by a heating device outside the mold 8 to cause them to crust.

[0056] In this embodiment, the high-pressure air generated by the air compressor 1 is output through the first output pipeline 11 and the second output pipeline 12 respectively, and the sand grains in the first sand box 2 and the second sand box 3 flow into the first output pipeline 11 and the second output pipeline 12 respectively under the action of gravity. Among them, since the cross-sectional area (pipe diameter) of the first output pipeline 11 gradually decreases along the gas flow direction, that is, the pipeline space gradually decreases, during the flow of the high-pressure gas in the first output pipeline 11, the gas continuously accumulates and squeezes, and then gradually heats up. After the gas in the first output pipeline 11 is heated, it transfers heat to the sand grains to preheat the sand grains. The high-temperature and high-pressure gas output from the first output pipeline 11 carries the preheated sand grains into the first sand shooting cylinder 4. The internal space surrounded by the inner cylinder 41 and the outer cylinder 42 of the first sand shooting cylinder 4 is a hollow columnar shape, and the internal space is small. Compared with the conventional cylindrical structure, it will not cause excessive pressure drop and temperature drop due to the sudden increase in space after the gas-solid two-phase in the first output pipeline 11 flows in, and the temperature and pressure of the gas-solid two-phase are kept relatively stable. The annular outlet of the first sand shooting cylinder 4 can output an annular sand beam. The annular sand beam is a sand beam preheated by the first output pipeline 11. After being output into the mold 8, it is mainly distributed around the mold 8. The sand grains output from the second output pipeline 12 enter the second sand shooting cylinder 5. The second sand shooting cylinder 5 is installed in the middle of the first sand shooting cylinder 4, that is, the second sand shooting cylinder 5 is inserted into the space in the middle of the first sand shooting cylinder 4. The circular sand column shot out by the second sand shooting cylinder 5 fills the middle of the mold 8, and finally a sand core with preheated sand grains on the outside and normal sand grains in the middle is obtained in the mold 8. The sand grains around the mold 8 are used to be heated by the heating device to crust, and the preheated sand grains can be heated to the preset temperature (crusting temperature 150-350 °C) faster under the action of the heating device.

[0057] It should be noted that the sand grains in the first sand box 2 are more dispersed at the beginning in the first output pipeline 11, which is convenient for uniform heating. As the pipe diameter decreases, they gradually become denser, and finally enter the first sand shooting cylinder 4 in a relatively dense state for sand shooting.

[0058] It can be understood that, compared with the second output pipeline 12, since the first output pipeline 11 needs to further compress the air to increase the temperature, therefore, two air compressors 1 can be respectively connected to the first output pipeline 11 and the second output pipeline 12, and among them, the compressor connected to the first output pipeline 11 can be a high-power compressor.

[0059] It should be noted that since the first sand box 2 and the second sand box 3 are sealed, the high-pressure gas in the first output pipeline 11 and the second output pipeline 12 cannot enter the first sand box 2 and the second sand box 3 and then be discharged into the atmosphere. Therefore, the high-pressure gas will not continuously enter the first sand box 2 and the second sand box 3 to form an air flow to hinder the falling of the sand grains.

[0060] It is understandable that the shapes of the first sand shooting cylinder 4, the second sand shooting cylinder 5 and the mold 8 can be adjusted according to the actual situation. For example, the first sand shooting cylinder 4 and the second sand shooting cylinder 5 can be cylindrical structures as shown in the appendix Figure 1 or elliptical cylinders or square cylinders. For example, the mold 8 can be a cuboid as shown in the appendix Figure 1 or a cylinder, etc.

[0061] In this embodiment, both the outlets of the first sand shooting cylinder 4 and the second sand shooting cylinder 5 can be provided with openable and closable baffles, and micropores that allow air to pass through but not sand can be provided on the baffles, so that after a certain amount of sand grains are accumulated in the first sand shooting cylinder 4 and the second sand shooting cylinder 5, the baffles can be opened to shoot sand. Rubber rings can also be provided at the outlets of the first sand shooting cylinder 4 and the second sand shooting cylinder 5 to achieve sealed contact with the first sand hole and the second sand hole of the mold 8. Of course, the rubber rings can also be provided on the first sand hole and the second sand hole.

[0062] In some embodiments of the present invention, both the inner cylinder 41 and the outer cylinder 42 include a conical part and a cylindrical part along the axis.

[0063] In this embodiment, after the sand grains enter the conical part, some sand grains will slide downward in a spiral manner in the space between the conical part of the inner cylinder 41 and the conical part of the outer cylinder 42. During the sliding process, due to the gradually shrinking circumference of the spiral motion, the linear velocity of the sand grains will increase, and the friction between the sand grains and the cylinder wall will also increase the temperature of the sand grains. Preferably, the outlet of the first output pipe 11 is obliquely downward and communicates with the conical space of the first sand shooting cylinder 4, and a spiral track plate or spiral groove can also be provided to limit the spiral motion of the sand grains. The cylindrical parts of the outer cylinder 42 and the inner cylinder 41 form a cylindrical space, and the cylindrical space communicates with the smaller-diameter end of the conical space, which is conducive to the aggregation of sand grains here. The shape of the cylindrical space facilitates the sand grains inside to form a stable annular sand beam downward.

[0064] In some embodiments of the present invention, a heating chamber 6 is provided outside the mold 8, water is filled in the heating chamber 6, and the heating device includes a microwave device 7;

[0065] Heating the sand in the mold 8 by using the heating device outside the mold 8 to make it crust, including:

[0066] Applying microwaves to the heating chamber 6 by using the microwave device 7 to raise the temperature of the heating chamber 6, and the heating chamber 6 heats the mold 8 it wraps and the sand grains inside to form a crust.

[0067] In this embodiment, microwaves facilitate the rapid heating of water molecules. Water is added to the heating chamber 6, and the heating chamber 6 can be filled with water or not filled with water. The water in the heating chamber 6 can be rapidly heated under the action of the microwave device 7, and then the heat is conducted to the sand core to rapidly form a shell. Microwave heating is more energy-efficient and has a faster heating speed.

[0068] In some embodiments of the present invention, the mold 8 is provided with exhaust holes 81, and a filter screen is installed on the exhaust holes 81. The mesh of the filter screen is smaller than the particle size of the sand grains. The exhaust holes 81 are communicated with the heating chamber 6 through an atomization pipeline 9. A piston device 91 is arranged in the atomization pipeline 9. The piston device 91 divides the atomization pipeline 9 into two parts. The part of the atomization pipeline 9 communicated with the exhaust holes 81 is the gas phase, and the part of the atomization pipeline 9 communicated with the heating chamber 6 is the water phase. The atomization pipeline 9 is communicated with the heating chamber 6 through an atomization nozzle 92.

[0069] The gas discharged from the exhaust holes 81 pushes the piston device 91 to spray the water in the atomization pipeline 9 into the heating chamber 6 through the atomization nozzle 92.

[0070] In this embodiment, after the sand grains fill the mold 8, the air compressor 1 is still used to pressurize the sand grains in the mold 8. In order to prevent the pressure in the mold 8 from being too high, the excess air pressure is discharged through the exhaust holes 81 so that the pressure in the mold 8 is maintained within a certain range. In the embodiment of the present invention, the exhaust holes 81 are communicated with the atomization pipeline 9, and the excess air pressure enters the atomization pipeline 9 through the exhaust holes 81. A piston device 91 is arranged in the atomization pipeline 9, and the air pressure conducts the pressure to the atomization pipeline 9 filled with water through the piston device 91. The piston device 91 compresses the water in the atomization pipeline 9 to be sprayed out through the atomization nozzle 92 into the heating chamber 6. The atomized water is more likely to fill the heating chamber 6 and is more likely to be heated evenly and rapidly under the action of the microwave device 7. In addition, in addition to providing pressure atomization, the piston device 91 can also pressurize the heating chamber 6 to further increase the heating rate. The pressure discharged from the exhaust holes 81 can also be recycled to reduce energy consumption.

[0071] It should be noted that the heating chamber 6 can be of any shape adapted to the mold 8 and is wrapped outside the mold 8. In order to clearly express the connection relationship in the present invention, only a partial part of the heating chamber 6 is shown in a simple shape.

[0072] In some embodiments of the present invention, the piston device 91 includes a housing 913, a first piston 911, and a second piston 912. The housing 913 includes a first part and a second part that are communicated with each other. The cross-sectional area of the first part is smaller than that of the second part. The first piston 911 is slidably and sealingly installed in the first part, and the second piston 912 is slidably and sealingly installed in the second part. The space formed by the first piston 911, the second piston 912, and the housing 913 is filled with a liquid.

[0073] In this embodiment, the piston device 91 needs to atomize and pressurize the heating chamber 6, and a relatively large pressure is required. Therefore, the areas of the first piston 911 and the second piston 912 are set differently. By using the area difference between the two and based on the hydraulic principle, the pressure received at the first piston 911 is multiplied and transmitted to the second piston 912 to enable it to have sufficient pressure.

[0074] In some embodiments of the present invention, a pressure relief valve 93 is installed on the atomization pipeline 9.

[0075] In some embodiments of the present invention, baffles are provided at the outlets of the first sand box 2 and the second sand box 3 to adjust the sand output of the two.

[0076] In this embodiment, after the pressure-holding heating stage after sand injection, the first sand box 2 and the second sand box 3 can be completely blocked by the baffle.

[0077] In some embodiments of the present invention, the sand grains in the first sand box 2 and the second sand box 3 contain phenolic resin.

[0078] In some embodiments of the present invention, flow regulating valves are installed on the first output pipeline 11 and the second output pipeline 12.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A manufacturing process for rapid crust formation of a core, characterized in that, Including: Turn on the air compressor so that the compressed air output therefrom enters the first output pipeline and the second output pipeline respectively; wherein, the cross-sectional area of the first output pipeline gradually decreases along the gas flow direction so as to increase the pressure and temperature of the compressed air therein; Output sand grains from the first sand box to the first output pipeline and output sand grains from the second sand box to the second output pipeline; The gas output from the first output pipeline is mixed with the sand grains output from the first sand box and then enters the first sand injection cylinder; wherein, the first sand injection cylinder includes an inner cylinder and an outer cylinder both in a cylindrical shape, the space formed between the inner cylinder and the outer cylinder is communicated with the first output pipeline, and one end of the first sand injection cylinder is surrounded by the outer cylinder and the inner cylinder to form an annular outlet for ejecting an annular sand beam; The gas output from the second output pipeline carries the sand grains output from the second sand box and then enters the second sand injection cylinder; wherein, the second sand injection cylinder passes through the inner cylinder, and the outlet of the second sand injection cylinder is circular to eject a circular sand column within the annular sand beam; The first sand injection cylinder and the second sand injection cylinder inject sand into the mold through an annular first sand hole and a circular second sand hole on the mold respectively; Heat the sand grains in the mold by using a heating device outside the mold to make them crust; A heating chamber is arranged outside the mold, water is filled in the heating chamber, and the heating device includes a microwave device; Heating the sand in the mold by using a heating device outside the mold to make it crust, including: Applying microwaves to the heating chamber by using the microwave device to raise the temperature of the heating chamber, and the heating chamber heats the mold wrapped by it and the sand grains therein to form a crust; The mold is provided with exhaust holes, a filter screen is installed on the exhaust holes, the mesh of the filter screen is smaller than the particle size of the sand grains, the exhaust holes are communicated with the heating chamber through an atomization pipeline, a piston device is arranged in the atomization pipeline, the piston device divides the atomization pipeline into two parts, the part of the atomization pipeline communicated with the exhaust holes is the gas phase, the part of the atomization pipeline communicated with the heating chamber is the water phase, and the atomization pipeline is communicated with the heating chamber through an atomization nozzle; The gas discharged from the exhaust holes pushes the piston device to spray the water in the atomization pipeline into the heating chamber through the atomization nozzle; The piston device includes a housing, a first piston and a second piston, the housing includes a first part and a second part which are communicated with each other, the cross-sectional area of the first part is smaller than that of the second part, the first piston is slidably and sealingly installed in the first part, the second piston is slidably and sealingly installed in the second part, and the space formed by the first piston, the second piston and the housing is filled with liquid.

2. The manufacturing process of a core with rapid crust formation according to claim 1, characterized in that Both the inner cylinder (41) and the outer cylinder (42) include a conical part and a cylindrical part along the axis.

3. The manufacturing process of a rapid crust formation of a core according to claim 1, characterized in that, A pressure relief valve (93) is installed on the atomization pipeline (9).

4. The manufacturing process of a core with rapid crust formation according to claim 1, characterized in that, Baffles are arranged at the outlets of the first sand box (2) and the second sand box (3) to adjust the sand output amounts of the two.

5. The manufacturing process of a core with rapid shell formation according to claim 1, characterized in that, The sand grains in the first sand box (2) and the second sand box (3) contain phenolic resin.

6. The manufacturing process of a core with rapid crust formation according to claim 1, characterized in that, Flow regulating valves are installed on the first output pipeline (11) and the second output pipeline (12).

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