A mold for core making equipment and its curing method and application

Abstract

The present invention discloses a mold for core making equipment and its curing method and application, belonging to the technical field of core making machine molds. The curing method includes the following steps: sand shooting molding, in the mold closing state, molding sand is shot into the mold cavity from the sand shooting nozzle on the mold body to form a sand core; heating and curing, using multiple air inlet channels to inject a curing medium heated to a gaseous state into the mold cavity, diffuse and penetrate after contacting the circumference of the sand core, and solidify it from all sides of the sand core, and the air inlet end of the air inlet channel is separated from the sand shooting nozzle. Through the present invention, it is achieved that the molding sand shot into the mold can be quickly and evenly attached to the core pulling surface, and various parts of the sand core can be quickly and evenly cured in a short time, which greatly accelerates the curing speed of large and high parts, improves the curing effect and efficiency, and can increase the compactness of the sand core by vibration, further improving the quality of the product.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of core making machine molds, and specifically relates to a mold for core making equipment and a curing method and application thereof. Background Art

[0002] Core making machine is a general term for core shooting machine, cold core machine and shell core machine, which mainly includes sand shooting mechanism, mold clamping mechanism, heat curing box and core pulling and demoulding mechanism. The core making machine shoots sand core into the core box at high speed. Under certain temperature conditions, high temperature gas is passed through the core box to make the sand core in the core box quickly form and harden to obtain the finished product. A cycle cycle only takes a dozen to dozens of seconds to produce sand cores for casting. The cores made by the core making machine are precise in size and smooth in surface, and are widely used in the casting machinery industry.

[0003] In the molds currently used in core making machines, general cold and hot core molds are generally cured by injecting gas through the sand shooting port located at the top of the mold to solidify the sand core. That is, sand shooting and gas injection share the same hole. This design method will cause the sand on the mold far away from the sand shooting port to not be cured quickly, making the sand core solidification uneven, greatly reducing the quality of the sand core product. Moreover, for those large and high parts, injecting gas from the sand shooting port at the top of the mold will make the gas penetrate into the sand more slowly and take longer, which greatly reduces the work efficiency.

[0004] As previously applied for by the applicant, the patent name is a positive and negative pressure sand shooting mechanism for a core making machine, and the patent application number is 2022110845390. In the sand shooting mechanism, the sand and curing gas are injected through the sand shooting port on the top, and the curing gas contacts the outer surface of the sand core for curing treatment. Since the curing gas is sprayed in from the top, it is difficult for the curing gas to evenly cure various areas of the sand core, and uneven curing will occur. Especially for large or high sand cores, the curing effect at the bottom is very poor, and if it is cured from the upper sand shooting port, it is very likely that the outer surface of the sand core has been completely cured, but its bottom and interior are still in an uncured state, resulting in uneven curing and poor curing effect.

[0005] In addition, since the curing gas is usually high-temperature hot gas, after being injected from the top sandblasting port, the curing gas is likely to overflow from the sandblasting port after the injection is completed, resulting in a reduction of the curing gas in the cavity, affecting the curing effect, and increasing the curing cost.

[0006] In view of the above problems, the applicant of the present invention has developed a forming and curing mold and a curing method for core making equipment after continuous and in-depth research. The mold separates the sand shooting port from the curing gas injection port, and significantly improves the curing effect by changing the curing method, making it more suitable for the curing treatment of large sand cores. Summary of the Invention

[0007] In order to solve the above technical problems, one of the purposes of the present invention is to provide a mold for core making equipment and its curing method and application, which separates the sand shooting port from the curing gas injection port, and significantly improves the curing effect by changing the curing method, making the curing more uniform and more suitable for the curing treatment of large sand cores.

[0008] The technical solution adopted by the present invention to solve the above technical problems is:

[0009] In a first aspect, the present invention provides a method for curing a mold for a core making device, comprising the following steps:

[0010] S1: Sand shooting molding: in the mold closing state, molding sand is shot into the mold cavity from the sand shooting nozzle on the mold body to form a sand core;

[0011] S2: Heating and curing, using multiple air inlet channels to inject the curing medium heated to a gaseous state into the mold cavity, diffuse and penetrate after contacting the surrounding side of the sand core, and solidify the sand core from all sides, and the air inlet end of the air inlet channel is separated from the sand shooting nozzle.

[0012] In some achievable embodiments of the first aspect, the solidifying medium heated to a gaseous state is injected into the inner cavity of the sand core through the plurality of air inlet channels, diffuses and penetrates into the inner wall thereof after contacting the inner cavity, and solidifies the sand core from the inside.

[0013] In some feasible methods of the first aspect, before the sand core is formed, the air inlet channel on the core pulling assembly is used to perform negative pressure vacuum treatment on the inside of the mold cavity, so that the molding sand in the mold cavity quickly adheres to the outer wall of the core pulling assembly and fills the inside of the mold cavity at the same time.

[0014] In some possible implementations of the first aspect, the curing medium includes at least one of a curing agent and a curing accelerator;

[0015] and / or, the curing agent comprises at least one of air, carbon dioxide, hexamethylenetetramine and citric acid;

[0016] And / or, the curing accelerator includes at least one of an amine curing accelerator, an acid anhydride curing accelerator, a metal salt curing accelerator and a silane coupling agent.

[0017] In some achievable methods of the first aspect, in the heating and curing step, heated air is injected into the mold cavity to cure the sand core from the inside. After curing is completed, the mold is opened and the core pulling assembly is removed to obtain the cured sand core.

[0018] In some possible implementations of the first aspect, in the heating and curing step, a curing agent or curing accelerator heated to a gaseous state is first injected into the mold cavity, and diffuses and penetrates into the side wall of the sand core cavity after contacting the curing agent or curing accelerator, thereby curing the curing agent from the inside of the sand core to achieve one-step curing.

[0019] The heated air is then injected into the mold cavity, and diffuses and penetrates into the side wall of the sand core cavity after contacting it, solidifying it from the inside of the sand core to achieve secondary solidification. After the solidification is completed, the mold is opened, and the core pulling assembly is removed to obtain the solidified sand core.

[0020] In some achievable methods of the first aspect, in the heating and curing step, the curing agent or curing accelerator heated to a gaseous state is mixed with the heated air, and the mixed gas is injected into the mold cavity to cure it from the inside of the sand core. After curing is completed, the mold is opened, and the core pulling assembly is removed to obtain the cured sand core.

[0021] In some possible implementations of the first aspect, the temperature of the heated air is 170° C. to 300° C.;

[0022] And / or, the pressure of the heated air is 0.1 MPa to 0.8 MPa

[0023] In a second aspect, the present invention provides an application of a method for curing a mold for a core-making device, wherein the method for curing a mold for a core-making device is used to cure molding sand.

[0024] The curing method is applicable to hot core or cold core processes;

[0025] And / or, the curing method is applicable to core making machines, core shooting machines, cold core machines and various core making equipment.

[0026] In a third aspect, the present invention provides a forming and curing mold for a core-making device, wherein the core-making device uses a curing method for a mold to cure molding sand, wherein the mold includes a core-pulling assembly and a mold body, wherein the core-pulling assembly and the mold body cooperate to form a cavity, wherein the cavity is used to form a sand core;

[0027] The mold body is provided with a sand-shooting nozzle, and the sand-shooting nozzle is located at the top of the mold cavity;

[0028] An air inlet channel is provided on the core pulling assembly, and an air outlet end of the air inlet channel is located in the inner cavity of the sand core. The air inlet channel is used to introduce gas into the inner cavity of the sand core and solidify the gas from inside the sand core.

[0029] In some achievable embodiments of the third aspect, the core pulling assembly includes a first core pulling assembly arranged along a first direction, the first core pulling assembly being used to form a first inner cavity of the sand core;

[0030] A first air outlet is provided on the circumferential side wall of the first core pulling member, a first air inlet is provided on the end surface of the first core pulling member that contacts the outside, and a first air inlet channel is formed between the first air inlet and the first air outlet;

[0031] And / or, the number of the first air outlet is not limited to one.

[0032] In some achievable embodiments of the third aspect, the core pulling assembly includes a second core pulling assembly arranged along a second direction, the second core pulling assembly being used to form a second inner cavity of the sand core;

[0033] A second air outlet is provided on the circumferential side wall of the second core pulling member, a second air inlet communicating with the outside is provided at the axial end of the second core pulling member, and a second air inlet channel is formed between the second air inlet and the second air outlet;

[0034] And / or, the number of the second air outlet is not limited to one.

[0035] In some possible implementations of the third aspect, the second core pulling means is a pair, symmetrically arranged on both sides of the first core pulling means;

[0036] And / or, the second core pulling device includes a core pulling body, the core pulling body is a cylindrical structure, and a second air outlet is formed on the end surface of the core pulling body located inside the cavity;

[0037] And / or, the core-pulling body includes an air inlet end face, the air inlet end face is used to close the inner cavity of the core-pulling body from the outside, and a second air inlet is provided on the air inlet end face.

[0038] In some possible implementations of the third aspect, an air intake pipe is installed in the inner cavity of the core pulling body, and the second air inlet and the second air outlet are connected through the air intake pipe;

[0039] The number of the air intake duct is not limited to one;

[0040] And / or, when the number of the air intake pipes exceeds one, the air intake end of each of the air intake pipes is connected to the second air intake port.

[0041] In some possible implementations of the third aspect, a third air outlet is provided through the circumferential side wall of the air inlet duct;

[0042] And / or, the number of the third air outlet is not limited to one.

[0043] In some achievable embodiments of the third aspect, there is a gap between the air intake duct and the core pulling body, and a third air outlet is provided on the side of the air intake duct away from the air intake end face, or the side of the air intake duct away from the air intake end face is open.

[0044] In some possible implementations of the third aspect, a vibrator is provided at an end of the first core pulling device facing away from the sand-shooting nozzle;

[0045] And / or, the number of the vibrators is not limited to one.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The present invention realizes rapid sandblasting from the upper part of the mold body into the mold cavity formed between the core pulling and the mold body through multiple sandblasting nozzles on the two mold bodies, and multiple air outlets on the first core pulling assembly and the second core pulling assembly realize negative pressure vacuum treatment of the inner cavity of the core pulling assembly from different directions and different parts. Under the negative pressure state, the molding sand in the mold cavity can quickly adhere to and fill various parts of the surface of the core pulling, shortening the time and making the distribution more uniform. Then, the positive pressure heated gas is injected into the inner cavity of the core pulling assembly, and enters the interior of the sand core through the air outlet, and contacts and diffuses with the inner wall of the sand core to achieve heating and curing of the sand core. When a curing agent is used, the curing agent will expand due to heat, accelerate penetration and diffusion, further improve the reinforcement effect, and improve the quality of the product.

[0048] (2) The present invention realizes rapid negative pressure vacuuming and positive pressure injection of a large amount of hot air in the inner cavity of the core pulling assembly through the design of multiple air inlet channels. The multiple air outlets on the first core pulling and the second core pulling greatly accelerate the speed of curing of the molding sand. At the same time, the degree of curing of the sand in each part of the mold cavity is the same, which is more uniform, thereby improving the curing effect and product quality. It is more suitable for large and high parts. Compared with the traditional core making machine mold, gas can only be injected from the sand shooting port on the top of the mold. The gas has poor penetration effect in the sand, which will cause problems such as slow speed, uneven diffusion, and long time. It also avoids the molding sand far away from the sand shooting port and cannot be better cured. It can quickly and evenly cure all parts of the sand core in a short time.

[0049] (3) The present invention achieves micro-vibration of different positions of the mold by setting a vibrator on the bottom plate to improve the fluidity of the sand, thereby improving the compactness of the sand core and further improving the quality of the sand core product.

[0050] (4) The traditional core making process is slow because it uses gas solidification from the sand injection port or single heating solidification. However, the present invention uses hot air to be injected into the mold cavity under positive pressure. Since the air pressure in the mold cavity is removed during negative pressure vacuuming, the hot air can quickly solidify the sand mold and sand core. Since the negative pressure vacuuming quickly absorbs the sand into the mold, the sand mold has good density, and then the hot air is solidified by multi-directional internal positive pressure, the solidification is uniform and fast, so the sand mold is of good quality and fast.

[0051] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 Schematic diagram of the overall structure of the mold for the core making equipment in an embodiment of the present invention;

[0053] Figure 2 Schematic diagram of the structure of the core pulling assembly in the mold according to an embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the overall exploded structure of the mold in an embodiment of the present invention;

[0055] Figure 4 Schematic diagram of the connection structure of the first core pulling in the mold according to an embodiment of the present invention;

[0056] Figure 5 for Figure 3 Enlarged schematic diagram of area A;

[0057] Figure 6 A schematic structural diagram of a sand core prepared according to an embodiment of the present invention;

[0058] Figure 7 This is a schematic structural diagram of the sand core prepared in an embodiment of the present invention from another perspective. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] 1. Core pull assembly; 11. Bottom plate; 12. First core pull; 121. Positioning block; 122. Sealing gasket; 123. First air outlet; 13. Arc-shaped bracket; 14. Second core pull; 15. Air inlet end face; 16. Second air inlet; 18. Second air outlet; 19. Exhaust plug; 2. Mold body; 21. Sandblasting nozzle; 22. Positioning groove; 23. Arc-shaped groove; 3. Positioning bracket; 4. Vibrator;

[0061] 5. Sand core; 51. First cavity; 52. Second cavity. DETAILED DESCRIPTION

[0062] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.

[0063] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly used by those skilled in the art to which the present invention pertains. The terminology used in the specification of the present invention is for the purpose of describing specific embodiments and is not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0065] The embodiment is to solve the problem that in the traditional sand-shooting mechanism, both the sand-shooting and the curing gas are injected through the sand-shooting port at the top, resulting in the sand core portion far away from the sand-shooting port having a poor curing effect, uneven curing, difficulty in complete curing inside, and easy overflow of the curing gas. The embodiment of the present invention provides a forming and curing mold for a core-making device, which is designed by separating the sand-shooting port from the curing gas injection port, and arranging the gas outlet end inside the inner cavity of the sand core 5, so that it is injected from the inside of the sand core 5 and contacts the inner wall of the sand core 5 for curing, and the curing gas is uniformly penetrated from the inside to the outside, which not only has a better curing effect and more uniform curing, but also can seal the curing gas inside the sand core 5, effectively preventing it from overflowing from the sand-shooting port, significantly improving the curing effect while making the curing more uniform, and is more suitable for the curing of large sand cores 5.

[0066] Specifically, please refer to the attached Figure 1-5 As shown, the mold includes a core pulling assembly 1 and a mold body 2, the core pulling assembly 1 and the mold body 2 cooperate to form a cavity, the cavity is used to form a sand core 5, and the mold body 2 is provided with a sand shooting nozzle 21, the sand shooting nozzle 21 is located at the top of the cavity. Figure 2 As shown, the mold body 2 is a symmetrical two-half design. In the mold closing state, as shown in FIG. Figure 1 As shown, the mold body 2 structure is enclosed to form an integral structure.

[0067] The mold cavity is formed by the outer wall of the core-pulling assembly 1 and the inner wall of the mold body 2. When the mold is closed, molding sand is injected into the mold cavity from a sand injection nozzle 21 at the top to form the desired sand core. It is understood that the core-pulling assembly 1 and the mold body 2 have different structures, and sand cores of different structures can be formed without further limitation.

[0068] In this embodiment, the core pulling assembly 1 is provided with an air inlet channel, the air inlet end of the air inlet channel being separated from the sand-shooting nozzle 21 on the top or side, and the air outlet end of the air inlet channel being located in the inner cavity of the sand core 5. The air inlet channel is used to introduce the heated solidifying gas into the inner cavity of the sand core 5 and solidify it from the inside of the sand core 5, thereby achieving diffusion and penetration from the inside of the sand core 5 to the outside, avoiding the problem of incomplete solidification inside the sand core 5, and achieving better and more uniform solidification. Since in the mold-closed state, the solidifying gas will be enclosed in the inner cavity of the sand core 5 after entering the inner cavity of the sand core 5, and will not cause the problem of solidifying gas overflowing and wasting.

[0069] It should be noted that there can be multiple air inlet channels. When there are multiple air inlet channels, the sand core 5 can be jet-cured from multiple directions, which improves the curing efficiency and has a better curing effect.

[0070] In some feasible embodiments, the core pulling assembly 1 includes a first core pulling assembly 12 arranged along a first direction, and the first core pulling assembly 12 is used to form the first inner cavity 51 of the sand core 5. Figure 2 In the orientation shown in , the first direction here refers to the vertical height direction.

[0071] In this embodiment, a first air outlet 123 is provided on the circumferential side wall of the first core pull 12. A first air inlet is provided on the end surface of the first core pull 12 that contacts the outside world. A first air inlet channel is formed between the first air inlet and the first air outlet 123. The first air inlet channel enables curing from the bottom of the sand core 5, which can meet the curing requirements of large or high-molded sand cores 5. The number of the first air outlets 123 is not limited to one. When there are multiple first air outlets 123, they can be relatively evenly distributed on the outer circumferential side wall of the first core pull 12.

[0072] Specifically, the first core pulling part 12 includes a first core pulling part body having a cavity structure in a first direction. The bottom of the first core pulling part body is provided with a bottom plate 11, and the bottom plate 11 is provided with a plurality of first air inlets. The top of the first core pulling part body is provided with an arc-shaped bracket 13, which is used to support the second core pulling part 14. The arc-shaped brackets 13 are a pair, symmetrically arranged on both sides of the top of the first core pulling part body, and the mold body 2 is provided with an arc-shaped groove 23 at a position corresponding to the arc-shaped bracket 13. In the mold closing state, the arc-shaped bracket 13 is embedded in the arc-shaped groove 23. The mutual cooperation between the arc-shaped groove 23 and the arc-shaped bracket 13 improves the stability of the internal structural connection of the mold.

[0073] Please refer to the attached Figure 2 and 3 As shown, attached Figure 2 and 3As shown, positioning blocks 121 are provided on both side walls of the first core pulling body, and positioning grooves 22 matching the positioning blocks 121 are provided on the inner side walls of the mold body 2, and the positioning blocks 121 are embedded in the positioning grooves 22 to achieve connection stability between the core pulling assembly 1 and the mold body 2 in the mold closing state.

[0074] In some feasible embodiments, the core pulling assembly 1 includes a second core pulling assembly 14 arranged along the second direction, the second core pulling assembly 14 is used to form the second inner cavity 52 of the sand core 5, and the second inner cavity 52 of the sand core 5 is connected to the first inner cavity 51. Figure 2 In the orientation shown in , the second direction here refers to the horizontal direction.

[0075] In this embodiment, a second air outlet 18 is provided on the circumferential side wall of the second core pull 14, and a second air inlet 16 communicating with the outside is provided at the axial end of the second core pull 14. A second air inlet channel is formed between the second air inlet 16 and the second air outlet 18. The second air inlet channel enables curing from the top of the sand core 5, curing the sand core 5 from different height positions, resulting in more uniform curing and better curing effect. Simultaneous jet curing at multiple locations can also significantly improve curing efficiency. The number of the second air outlets 18 is not limited to one. When there are multiple second air outlets 18, they can be evenly distributed on the circumferential side wall of the second core pull 14.

[0076] Preferably, in this embodiment, the second core pull 14 is a pair, symmetrically arranged on both sides of the first core pull 12. The second core pull 14 includes a second core pull body, which is a cylindrical structure, and a second air outlet 18 is opened on the end surface of the second core pull body located inside the mold cavity, ensuring that the second core pull body has multiple air outlets in different directions, the air outlet is more uniform, and can achieve multi-channel and multi-directional gas diffusion and penetration, thereby improving the curing effect.

[0077] like Figure 2 As shown, in this embodiment, the second core-pulling body includes an air inlet end face 15, which is used to close the inner cavity of the second core-pulling body from the outside, and a second air inlet port 16 is provided on the air inlet end face 15. The number of the second air inlet ports 16 here is not limited to one, which facilitates the realization of multiple air inlet channels.

[0078] Furthermore, in this embodiment, an air inlet pipe is installed in the inner cavity of the second core-pulling body, and the second air inlet 16 and the second air outlet 18 are connected through the air inlet pipe. Figure 2As shown, the air inlet channel can be a cylindrical structure that matches the inner cavity of the second core-pulling body, or it can be of other structural forms, as long as the air inlet channel has a certain inner cavity and can transport the solidified gas into the inner cavity of the second core-pulling body. The number of the air inlet ducts is not limited to one. When the number of the air inlet ducts exceeds one, the air inlet end of each of the air inlet ducts is connected to the second air inlet port 16.

[0079] In this embodiment, a third air outlet is provided through the circumferential sidewall of the air intake duct, and the number of third air outlets is not limited to one. Alternatively, a gap is provided between the air intake duct and the core-pulling body, and the third air outlet is provided on the side of the air intake duct away from the air intake end face 15, or the side of the air intake duct away from the air intake end face 15 is open.

[0080] It should be noted that the air inlet pipe transports solidified gas into the inner cavity of the second core pulling body, and it can be output from the circumferential side wall openings of the air inlet pipe, or from the open-designed air outlet pipe of the air inlet pipe, or from the through hole on the end face of the closed air outlet pipe. Any of the three forms can be selected, or any combination can be made. It is only necessary to transport the solidified gas in the air inlet pipe to the inner cavity of the second core pulling body and output it through the second air outlet 18 on the second core pulling body.

[0081] In some feasible embodiments, a vibrator 4 is provided at the end of the first core pulling machine 12 facing away from the sand shooting nozzle 21, and the number of vibrators 4 is not limited to one. The vibration of the vibrator 4 not only improves the fluidity of the sand, but also vibrates and compacts the sand injected into the mold cavity, thereby improving the compactness and quality of the sand core product.

[0082] In this embodiment, the first core pulling 12 and the bottom plate 11 are connected by bolts, and a circle of sealing gasket 122 is provided at the lower edge of the bottom of the first core pulling 12. The sealing gasket 122 improves the sealing performance of the connection between the first core pulling 12 and the bottom plate 11, thereby avoiding sand leakage.

[0083] Preferably, in this embodiment, each of the first air outlet 123 and the second air outlet 18 can be provided with an exhaust plug 19. When the inner cavity of the core pulling assembly is vacuumed at negative pressure or injected with positive pressure high-temperature gas, the sand is prevented from passing through the first air outlet 123 and the second air outlet 18 with the air flow. On the premise of achieving ventilation to the interior of the sand core 5, the purpose of isolating the sand is achieved, the air and sand are separated, and the sand is prevented from entering the internal cavity of the core pulling assembly.

[0084] In another aspect, the present invention provides a method for curing a mold for a core making device, wherein the molding sand is cured using the above-mentioned molding and curing mold. The curing method comprises the following steps:

[0085] S1: Sand shooting molding, in the mold closed state, molding sand is injected into the mold cavity from the sand shooting nozzle 21 on the mold body 2 to form a sand core 5 (which can be called a sand mold);

[0086] S2: Heating and curing, using multiple air inlet channels to inject the curing medium heated to a gaseous state into the mold cavity, diffuse and penetrate after contacting the sides of the sand core 5, and uniformly cure the sand core 5 from all sides, and the air inlet end of the air inlet channel is separated from the sand shooting nozzle 21. In the traditional process, due to gas curing or single heating curing through the sand shooting nozzle 21, not only is the curing uneven and the curing speed slow, but the part of the sand core far away from the sand shooting nozzle 21 will also be incompletely cured, especially when it comes to large or high-profile sand core products. In this embodiment, air is simultaneously introduced into the mold cavity through multiple air inlet channels, and the sand core 5 is subjected to hot gas curing treatment from different directions, which can effectively solve the problems of uneven and incomplete curing and slow curing speed, and effectively improve the quality of the sand core product.

[0087] In some possible implementations, the solidifying medium heated to a gaseous state is injected into the inner cavity of the sand core 5 through the plurality of air inlet channels, diffuses and penetrates into the inner wall of the sand core 5 after contact, and solidifies the sand core 5 from within. In practice, due to the different structures of the prepared sand core products, the air inlet channels can be provided on the core pulling assembly 1 or the mold.

[0088] In this embodiment, the curing medium includes at least one of a curing agent and a curing accelerator, wherein the curing agent includes at least one of air, carbon dioxide, hexamethylenetetramine and citric acid; and / or the curing accelerator includes at least one of an amine curing accelerator, an acid anhydride curing accelerator, a metal salt curing accelerator and a silane coupling agent.

[0089] There are three specific curing methods:

[0090] (1) The first curing method includes the following steps:

[0091] S1: In the mold closing state, molding sand is injected into the mold cavity from the sand injection nozzle on the mold body to form the sand core 5;

[0092] S2: The heated air is injected into the mold cavity through the air inlet channel on the core pulling assembly, and diffuses and penetrates into the inner side wall of the sand core 5 after contacting it, and solidifies it from the inside of the sand core 5. After solidification is completed, the mold is opened, and the core pulling assembly is taken out to obtain the solidified sand core 5.

[0093] Specifically, the heated air is injected into the inner cavity of the sand core 5 through multiple first air inlet channels and the second air inlet channel, which greatly accelerates the curing speed of the molding sand. At the same time, the degree of curing of the sand in each part of the mold cavity is the same, which is more uniform, thereby improving the curing effect and product quality, and is more suitable for large and high parts. Compared with the traditional core making machine mold, gas can only be injected from the sand shooting nozzle on the top of the mold. The gas has poor penetration effect in the sand, which will cause slow speed, uneven diffusion, and long time. It also avoids the molding sand far away from the sand shooting port and cannot be better cured. The defect can be achieved that all parts of the sand core 5 can be quickly and evenly cured in a short time.

[0094] In addition, since the solidification air inlet channel is directly connected to the mold, no extra moving structure is required, which greatly saves core making time and manufacturing costs. It can also be solidified by heating the gas to promote the acceleration of the reaction speed of the curing agent in the sand mold.

[0095] (2) The second curing method includes the following steps:

[0096] S1: In the mold closing state, molding sand is injected into the mold cavity from the sand injection nozzle on the mold body to form the sand core 5;

[0097] S2: using the air inlet channel on the core pulling assembly to first inject the heated gaseous curing agent or curing accelerator into the mold cavity, and diffuse and penetrate into the side wall of the inner cavity of the sand core 5 after contact, and solidify it from the inside of the sand core 5 to achieve primary curing;

[0098] S3: The heated air is then injected into the mold cavity, and diffuses and penetrates into the inner side wall of the sand core 5 after contacting it, and solidifies it from the inside of the sand core 5 to achieve secondary solidification. After the solidification is completed, the mold is opened, and the core pulling assembly is taken out to obtain the solidified sand core 5.

[0099] Specifically, carbon dioxide heated to a gaseous state (in practice, other gaseous curing agents or curing accelerators, such as triethylamine, can also be selected according to actual conditions) and heated air are injected into the inner cavity of the sand core in two batches through multiple first air inlet channels and second air inlet channels. When the curing agent is heated to a gaseous state, its volume continues to expand, reducing the amount of curing agent or curing accelerator and increasing the contact area with the sand core. It is first introduced into the inner cavity of the sand core 5 to complete the primary curing, and then the heated air is introduced to perform secondary curing on the sand core 5, which has a better curing effect.

[0100] (3) The third curing method includes the following steps:

[0101] S1: In the mold closing state, molding sand is injected into the mold cavity from the sand injection nozzle on the mold body to form the sand core 5;

[0102] S2: After mixing the curing agent or curing accelerator heated to a gaseous state with air, the mixed gas is injected into the mold cavity through the air inlet channel on the core pulling assembly, and diffuses and penetrates into the inner cavity side wall of the sand core 5 after contacting it, and solidifies it from the inside of the sand core 5. After the solidification is completed, the mold is opened, and the core pulling assembly is taken out to obtain the solidified sand core 5.

[0103] Specifically, carbon dioxide heated to a gaseous state (in practice, other gaseous curing agents or curing accelerators, such as triethylamine, may also be selected according to actual conditions) and heated air are mixed and then injected into the inner cavity of the sand core 5 through multiple first air inlet channels and second air inlet channels. When the curing agent is heated to a gaseous state, its volume continues to expand, increasing the contact area with the sand core 5. After mixing with the hot air, it can effectively improve the curing effect.

[0104] Preferably, among the three curing methods described above, before the sand core 5 is formed, the air inlet channel on the core pulling assembly is used to perform a negative pressure vacuum treatment on the interior of the mold cavity. In practice, the negative pressure vacuum treatment can be performed before or during the sand shooting, so that the molding sand in the mold cavity quickly adheres to the outer wall of the core pulling assembly and simultaneously fills various parts of the mold cavity, which not only makes the molding sand more evenly distributed and improves the quality of the subsequent molded product, but also effectively shortens the molding time and improves the molding efficiency. Then, the interior of the sand core 5 is heated and cured using the heated curing gas under positive pressure, which greatly accelerates the curing speed and improves the curing effect, especially for large and high-quality products. Because curing from the top sand nozzle and from the outside of the sand core 5 is performed, the gas diffusion and penetration effect is poor and the speed is slow, and it is easy to cause the sand core part near the sand shooting nozzle to be over-cured, while the part far from the sand shooting nozzle has not yet reached complete curing. In addition, it is easy to cause the internal curing to be incomplete, which is easy to cause product quality problems.

[0105] The curing method of using negative pressure vacuuming combined with positive pressure input of a gaseous curing medium in this embodiment has the following advantages:

[0106] 1. Since the traditional core making process is a single sand shooting through the sand shooting port, air pressure resistance is generated in the mold cavity, so the molding speed is slow. In this embodiment, the gas in the mold cavity and the gas during sand shooting are quickly extracted from the mold by negative pressure vacuuming, and the sand is also quickly adsorbed to various parts of the mold to form a rapid molding.

[0107] 2. While traditional core-making processes rely on gas curing from a sand injection port or single-heat curing, resulting in slow curing, this embodiment uses positive pressure injection of hot air into the mold cavity. Since negative pressure vacuuming removes the air pressure within the mold cavity, the hot air can rapidly solidify the sand mold and core. Because negative pressure vacuuming quickly draws sand into the mold, the sand mold has a high density. Then, the multi-directional positive pressure curing of hot air ensures uniform and rapid curing, resulting in high-quality sand molds and rapid production.

[0108] 3. The exhaust channel of the mold through the positive and negative pressure process is not easy to be blocked and the exhaust is unobstructed because the carbon deposits and residual resin in the exhaust channel are cleaned during the positive and negative pressure process.

[0109] 4. During sand shooting, the sand shooting pressure can be greatly reduced due to the assistance of negative pressure vacuum, thereby reducing carbon deposits on the mold and reducing mold wear, thereby greatly improving the service life of the mold. It can also effectively clean or reduce carbon deposits and waste sand on the mold, keep the mold clean, thereby ensuring the quality of the sand mold or sand core, and reducing the mold cleaning process or cleaning time.

[0110] In some feasible embodiments, the temperature of the heated air is 170°C to 300°C, and the pressure of the heated air is 0.1 MPa to 0.8 MPa, which is the safe operating pressure range of hot air to ensure the safety of the curing operation.

[0111] The curing agent includes at least one of carbon dioxide, hexamethylenetetramine, citric acid, and a silane coupling agent. When heated, the curing agent expands significantly in volume, increasing the contact area with the sand core 5, enabling rapid curing of the sand core 5, enhancing the strength and stability of the sand core 5, and improving its moisture resistance and high temperature resistance. Furthermore, the curing agent can reduce the porosity of the sand core 5 and improve the surface quality of the casting.

[0112] Finally, an embodiment of the present invention further provides an application of a method for curing a mold for a core-making device, wherein the method for curing a mold for a core-making device is used to cure molding sand.

[0113] The curing method is applicable to hot core or cold core processes, and the curing method is applicable to core making machines, core shooting machines, cold core machines and various core making equipment.

[0114] The above description of the present invention is exemplified in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as such non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A forming and curing mold for core making equipment, characterized in that: The mold comprises a core pulling assembly (1) and a mold body (2), wherein the core pulling assembly (1) and the mold body (2) cooperate to form a mold cavity, and the mold cavity is used to form a sand core (5); The mold body (2) is provided with a sand ejection nozzle (21), and the sand ejection nozzle (21) is located at the top or side of the mold cavity; An air inlet channel is provided on the core pulling assembly (1), the air outlet end of the air inlet channel is located in the inner cavity of the sand core (5), and the air inlet channel is used to introduce gas into the inner cavity of the sand core (5) and solidify the gas from inside the sand core (5); The core pulling assembly (1) comprises a first core pulling assembly (12) arranged along a first direction and a second core pulling assembly (14) arranged along a second direction, and the second core pulling assembly (14) is a pair of the first core pulling assembly (12) and is symmetrically arranged on both sides of the first core pulling assembly (12). The first core pulling assembly (12) is used to form a first inner cavity (51) of the sand core (5), and the second core pulling assembly (14) is used to form a second inner cavity (52) of the sand core (5). A first air outlet (123) is provided on the circumferential side wall of the first core puller (12), a first air inlet is provided on the end surface of the first core puller (12) in contact with the outside, and a first air inlet channel is formed between the first air inlet and the first air outlet (123); A second air outlet (18) is provided on the circumferential side wall of the second core puller (14), a second air inlet (16) communicating with the outside is provided at the axial end of the second core puller (14), and a second air inlet channel is formed between the second air inlet (16) and the second air outlet (18); The second core pulling device (14) comprises a core pulling body, the core pulling body is a cylindrical structure, and a second air outlet (18) is provided on the end surface of the core pulling body located inside the cavity; The core-pulling body comprises an air inlet end surface (15), the air inlet end surface (15) is used to close the inner cavity of the core-pulling body from the outside, and a second air inlet (16) is provided on the air inlet end surface (15).

2. The forming and curing mold for core making equipment according to claim 1, characterized in that: The number of the first air outlet (123) is not limited to one.

3. The forming and curing mold for core making equipment according to claim 1, characterized in that: The number of the second air outlet (18) is not limited to one.

4. The forming and curing mold for core making equipment according to claim 1, characterized in that: An air intake pipe is installed in the inner cavity of the core pulling body, and the second air inlet (16) and the second air outlet (18) are connected through the air intake pipe; The number of the air intake duct is not limited to one; When the number of the air intake pipes exceeds one, the air intake end of each of the air intake pipes is connected to the second air intake port (16).

5. The forming and curing mold for core making equipment according to claim 4, characterized in that: The circumferential side wall of the air inlet duct is provided with a third air outlet running through it; The number of the third air outlet is not limited to one.

6. The forming and curing mold for core making equipment according to claim 4, characterized in that: There is a gap between the air intake duct and the core pulling body, and a third air outlet is provided on the side of the air intake duct away from the air intake end face (15), or the side of the air intake duct away from the air intake end face (15) is open.

7. The forming and curing mold for core making equipment according to claim 1, characterized in that: A vibrator (4) is provided at the end of the first core pulling (12) facing away from the sand-shooting nozzle (21); The number of the vibrators (4) is not limited to one.

8. A method for curing a mold for a core-making device, using the forming and curing mold for a core-making device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Sand shooting molding, in the mold closing state, molding sand is shot into the mold cavity from the sand shooting nozzle (21) on the mold body (2) to form the sand core (5); S2: heating and curing. Before the sand core (5) is formed, the interior of the mold cavity is subjected to negative pressure vacuum treatment using multiple air inlet channels on the core pulling assembly (1), so that the molding sand in the mold cavity quickly adheres to the outer wall of the core pulling assembly (1) and fills the interior of the mold cavity at the same time; Then, the solidifying medium heated to a gaseous state is injected into the mold cavity through the same air inlet channel, diffuses and penetrates the peripheral side of the sand core (5) after contact, and solidifies the sand core (5) from all sides, and the air inlet end of the air inlet channel is separated from the sand shooting nozzle (21).

9. The method for curing a mold for core making equipment according to claim 8, wherein: The solidifying medium heated to a gaseous state is injected into the inner cavity of the sand core (5) through the plurality of air inlet channels, diffuses and penetrates into the inner wall of the sand core (5), and solidifies the sand core (5) from the inside.

10. The method for curing a mold for core making equipment according to claim 8, wherein: The curing medium includes at least one of a curing agent and a curing accelerator; The curing agent includes at least one of carbon dioxide, hexamethylenetetramine and citric acid; The curing accelerator includes at least one of an amine curing accelerator, an acid anhydride curing accelerator, a metal salt curing accelerator and a silane coupling agent.

11. The method for curing a mold for core making equipment according to claim 8, wherein: In the heating and curing step, heated air is injected into the mold cavity to cure the sand core (5) from the inside. After curing is completed, the mold is opened and the core pulling assembly (1) is taken out to obtain the cured sand core (5).

12. The method for curing a mold for core making equipment according to claim 8, wherein: In the heating and curing step, a curing agent or curing accelerator heated to a gaseous state is first injected into the mold cavity, and diffuses and penetrates into the inner cavity side wall of the sand core (5) after contacting the inner cavity side wall, and is cured from the inside of the sand core (5), thereby achieving one-step curing; The heated air is then injected into the mold cavity and diffuses and penetrates into the inner wall of the sand core (5) after contacting it, thereby curing it from the inside of the sand core (5) to achieve secondary curing. After the curing is completed, the mold is opened, and the core pulling assembly (1) is removed to obtain the cured sand core (5).

13. The method for curing a mold for core making equipment according to claim 8, wherein: In the heating and curing step, a curing agent or curing accelerator heated to a gaseous state is mixed with heated air, and the mixed gas is injected into the mold cavity to cure the sand core (5) from the inside. After the curing is completed, the mold is opened, and the core pulling assembly (1) is removed to obtain a cured sand core (5).

14. The method for curing a mold for core making equipment according to claim 11, wherein: The temperature of the heated air is 170°C to 300°C; And / or, the pressure of the heated air is 0.1 MPa to 0.8 MPa.

15. An application of a curing method for a mold for core making equipment, characterized in that: The molding sand is solidified using the solidification method for a core making equipment mold according to any one of claims 8 to 14; The curing method is applicable to hot core or cold core processes.

Images