Casting mold apparatus using temperature-controlled the chill

Abstract

A sand casting apparatus according to one embodiment of the present disclosure comprises: a mold formed of casting sand and forming a cavity into which molten metal can be filled; a cooling element disposed on one surface of the mold forming the cavity so as to be in direct contact with the molten metal, wherein the cooling element is disposed at a position corresponding to a relatively thick portion of the casting to be formed within the cavity; a temperature sensor attached to the cooling element to sense the temperature of the molten metal; a cooling channel formed within the cooling element to allow a cooling element to flow; and a control unit that controls the flow rate of the cooling element supplied to the cooling channel to correspond to a preset target cooling rate based on temperature data received from the temperature sensor.

Description

Technology Field

[0001] The present disclosure relates to a sand casting apparatus, and more specifically, to a sand casting apparatus capable of controlling the cooling rate of a molten metal by controlling the flow rate of a refrigerant based on the temperature of the molten metal. Background Technology

[0002] In a typical sand casting process, chillers are placed in the thicker sections of the casting to promote solidification. However, since conventional chillers are installed within the sand casting apparatus as metal blocks of predetermined material and volume, they possess a passive nature in that their cooling capacity cannot be altered once installed. Consequently, existing chillers cannot compensate for variations in cooling rates caused by factors such as changes in the temperature of the injected molten metal, which can compromise the quality of the casting.

[0003] Furthermore, when high-temperature molten metal comes into rapid contact with a cold metal surface, excessive thermal stress is generated during the solidification process, which can lead to the formation of cracks inside and on the surface of the casting or cause inhomogeneity in the metal structure. In addition, if condensation or gases caused by the temperature difference between the cold metal and the molten metal are not properly vented, defects such as blowholes often occur on the surface of the casting.

[0004] Therefore, there is a need for a sand casting device capable of monitoring the temperature of the molten metal through a chiller and changing the cooling performance to match the target cooling rate. The problem to be solved

[0006] One aspect of the present disclosure provides a sand casting apparatus capable of controlling the cooling rate of the molten metal by controlling the temperature of the cold metal during the sand casting process.

[0007] One aspect of the present disclosure provides a sand casting apparatus capable of preventing the fusion of molten metal and cold metal and controlling the heat transfer rate to improve the quality of the casting.

[0008] One aspect of the present disclosure provides a sand casting apparatus capable of smoothly discharging pores that occur between the molten metal and the cold metal. means of solving the problem

[0010] A sand casting apparatus according to one embodiment of the present disclosure comprises: a mold formed of casting sand and forming a cavity into which molten metal can be filled; a cooling element disposed on one surface of the mold forming the cavity so as to be in direct contact with the molten metal, wherein the cooling element is disposed at a position corresponding to a relatively thick portion of the casting to be formed within the cavity; a temperature sensor attached to the cooling element to sense the temperature of the molten metal; a cooling channel formed within the cooling element to allow a cooling element to flow; and a control unit that controls the flow rate of the cooling element supplied to the cooling channel to correspond to a preset target cooling rate based on temperature data received from the temperature sensor. Brief explanation of the drawing

[0012] FIG. 1 is a schematic diagram of a sand molding apparatus according to one embodiment of the present disclosure. Figure 2 is a perspective view of the cold metal of the sand molding device shown in Figure 1. Figure 3 is a schematic diagram of the sand casting apparatus shown in Figure 1. Figure 4 is a schematic diagram of the cold metal of the sand casting apparatus shown in Figure 1. Figure 5 is a schematic diagram of the sand casting apparatus shown in Figure 1. Figure 6 is a schematic diagram of the sand casting apparatus shown in Figure 1. Figure 7 is a control block diagram of the sand casting device shown in Figure 1. Specific details for implementing the invention

[0013] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and various modifications that may replace the embodiments and drawings of this specification may exist at the time of filing this application.

[0014] Additionally, the same reference numerals or symbols presented in each drawing of this specification represent parts or components that perform substantially the same function.

[0015] Furthermore, the terms used in this specification are for describing embodiments and are not intended to limit or / or restrict the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0016] Additionally, terms including ordinal numbers, such as "first," "second," etc., used herein may be used to describe various components, but said components are not limited by said terms, and said terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any one of a plurality of related described items.

[0017] Meanwhile, terms such as "front," "rear," "left," and "right" used in the following description are defined based on the drawings, and the shape and position of each component are not limited by these terms.

[0018] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the attached drawings.

[0019] FIG. 1 is a schematic diagram of a sand molding apparatus according to one embodiment of the present disclosure.

[0020] Referring to FIG. 1, the sand molding device (1) may include an injection port (2), a riser port (3), a mold (10), a cold plate (20), and a core (30). The injection port (2), the riser port (3), and the mold (10) may be formed using molding sand.

[0021] Molten metal can be introduced into the mold through the injection port (2). The injection port (2) can guide the molten metal into the mold. The injection port (2) may include a tapered shape.

[0022] Molten metal can be stored in the riser (3). The volume of the molten metal may decrease while it solidifies in the cavity (10a) inside the mold. Additional molten metal may be introduced through the riser (3), and the empty space in the cavity (10a) may be filled. Additionally, if there is no molten metal in the riser (3), gas in the cavity may be discharged to the outside of the cavity (10a) through the riser (3).

[0023] The mold (10) may be composed of molding sand. The molding sand may include silica sand or artificial sand and may be filled into a predetermined mold to form a mold.

[0024] A cavity (10a), which is an empty space corresponding to the shape of the casting, is formed inside the mold (10). The cavity (10a) is a space in which the injected molten metal cools and solidifies to form the casting, and a core (30) for forming a hollow part may be placed inside it.

[0025] In the mold (10), an injection port (2) for guiding molten metal from the outside into the cavity (10a) and a riser port (3) for replenishing molten metal during solidification shrinkage are formed in a shape that penetrates or is recessed in a part of the molding sand. The inner wall surfaces of the injection port (2) and the riser port (3) may be partitioned by the molding sand constituting the mold (10).

[0026] A cold plate (20) may be placed on one side of the mold (10). The cold plate (20) is placed at a specific location within the mold (10) (e.g., a location corresponding to a thick section of the casting) before the molding sand hardens. According to one embodiment, as the molding sand hardens, the cold plate (20) can be firmly fixed in position within the mold (10) by mechanical interlocking with the molding sand.

[0027] The cooling element (20) can locally control the cooling rate of the molten metal in the cavity (10a) during the sand casting process. The cooling element (20) is positioned at a location corresponding to a relatively thick section of the casting and can be one side of the mold (10) forming the cavity (10a). For example, one side of the cooling element (20) can be in contact with the molten metal (40).

[0029] FIG. 2 is a perspective view of the cold metal of the sand casting device shown in FIG. 1. FIG. 3 is a schematic diagram of the sand casting device shown in FIG. 1.

[0030] Referring to FIGS. 2 and FIGS. 3, the cold metal may include a contact portion and a tapered portion.

[0031] The contact portion (21) can absorb heat by coming into direct contact with the molten metal (40). The tapered portion (22) can extend from the contact portion (21) and be embedded inside the molding sand that forms the mold (10). The contact portion (21) and the tapered portion (22) can be formed integrally and can be made of a metal material with high thermal conductivity.

[0032] The above contact portion (21) forms one side of the mold (10) and is positioned to be exposed into the cavity (10a). Accordingly, the high-temperature molten metal (40) injected into the cavity (10a) comes into direct contact with the above contact portion (21), and the molten metal (40) is rapidly cooled through the contact portion (21), thereby improving the structural density of the casting and preventing defects caused by solidification shrinkage.

[0033] The tapered portion (22) may gradually increase in width and / or cross-sectional area along the direction away from the contact portion (21) and the molten metal (40) and cavity (10a). This reverse tapered structure is wedge-shaped between the molding sand particles forming the mold (10) and can form a strong mechanical interlocking force as the molding sand hardens.

[0034] Due to these structural features, even if strong flow pressure or pressure due to thermal expansion is applied to the cold metal (20) when the molten metal (40) is injected, the tapered portion (22) is supported by being caught on the molding sand, so the cold metal (20) can be prevented from being pushed into the cavity (10a) or displaced from its position.

[0036] Figure 4 is a schematic diagram of the cold metal of the sand casting apparatus shown in Figure 1.

[0037] Referring to FIG. 4, the sand casting device may further include a gas discharge section (23). The cold metal (20) may further include a gas discharge section (23) formed on one side of the contact section (21) that contacts the molten metal (40). At the moment the high-temperature molten metal (40) comes into contact with the cold metal (20), gas or air bubbles may be generated at the contact interface due to the temperature difference, and if these are not discharged quickly, defects such as blowholes may occur on the surface of the casting.

[0038] The gas discharge section (23) may have a fine groove and / or slot shape that is recessed from one side of the contact section (21). The gas discharge section (23) is spaced apart at regular intervals over the entire area in contact with the molten metal (40) to guide the gas to be smoothly discharged into the gaps between the molding sand of the mold (10) without any stagnant sections.

[0039] The gas flowing through the gas discharge section (23) can travel along the outer surface of the contact section (21) and the tapered section (22) and be dispersed and discharged among the molding sand particles inside the mold (10). In particular, the gas discharge section (23) is physically separated from the cooling channel (24) described later, so it can serve as a passage that selectively discharges only gas without affecting the flow of the refrigerant. Through this gas discharge structure, gas mixing defects that frequently occur at the installation site of the cold metal (20) can be prevented.

[0040] The sand casting device may further include a cooling channel (24). The cooling channel (20) may include a cooling channel (24). A cooling medium (water, air, oil, etc.) capable of absorbing heat transferred from the molten metal flows within the contact portion (21), and a cooling channel (24) is formed. The cooling channel (24) can increase cooling efficiency by rapidly discharging heat from the contact portion (21) that is in direct contact with the molten metal to the outside. The cooling channel (24) may be formed to penetrate the interior of the contact portion (21) and may be connected to an external cooling medium control device (see FIG. 7) to control the flow rate and velocity.

[0041] In order to maintain structural stability while simultaneously performing gas discharge and cooling, the gas discharge section (23) and the cooling channel (24) are spaced apart.

[0042] The gas discharge section (23) is formed as an open type structure recessed into the uppermost surface of the contact section (21), whereas the cooling channel (24) can be formed as a closed type structure inside the contact section (21) on the side further from the molten metal (40) than the gas discharge section (23).

[0043] The gas discharge section (23) and the cooling path (24) can be isolated so that they do not communicate with or interfere with each other. This prevents the refrigerant from leaking into the gas discharge section (23) and simultaneously ensures independent cooling performance and exhaust performance.

[0045] Figure 5 is a schematic diagram of the sand casting apparatus shown in Figure 1.

[0046] Referring to FIG. 5, the sand casting apparatus may include a coating layer (50a, 50b). The coating layer (50a, 50b) may be placed on the surface of the contact portion (21) that contacts the molten metal (40). The coating layer (50a, 50b) may also be a component included in the cold metal (20). The coating layer (50a, 50b) can prevent direct chilled-on between the molten metal (40) and the cold metal (20) and improve the quality of the casting by controlling the heat transfer rate.

[0047] The coating layer (50a, 50b) may include a first coating layer (50a) and a second coating layer (50b). The first coating layer (50a) is placed on the surface closest to the molten metal (40) and cavity (10a) of the contact portion (21) and may be made of a ceramic-based material with high refractory properties. For example, the first coating layer (50a) may be formed from at least one of zircon, alumina, and / or graphite.

[0048] The first coating layer (50a) can prevent the surface of the cold metal (20) from being damaged or sticking to the casting when exposed to high-temperature molten metal (40). This increases the reusability of the cold metal and prevents adhesion defects on the surface of the casting.

[0049] The second coating layer (50b) may be placed between the first coating layer (50a) and the contact portion (21). The second coating layer (50b) is intended to control the heat transfer rate to the cold metal (20) and may be formed of a material having a specific thermal conductivity. Through this, the level of quenching can be adjusted stepwise according to the type of molten metal (40) or the thickness of the casting, thereby preventing cracking of the casting due to rapid temperature changes and inducing a target microstructure.

[0050] The first coating layer (50a) and the second coating layer (50b) can be stacked sequentially. This multilayer coating structure is organically combined with the cooling channel (24) and gas discharge section (23) formed inside the cold metal (20) to provide a complex cooling solution of physical gas discharge, active flow rate control, and heat transfer gradient control on the surface.

[0052] Figure 6 is a schematic diagram of the sand casting apparatus shown in Figure 1.

[0053] Referring to FIG. 6, the cold metal (20) may include an inclined section (25) whose thickness varies in response to a section where the thickness of the casting (molten metal, 40) gradually changes. The inclined section (25) can prevent internal defects caused by uneven cooling by matching the heat capacity of the cold metal based on the difference in heat quantity according to the difference in thickness of the molten metal (40).

[0054] The inclined portion (25) may include an inclined surface in which the thickness gradually decreases or increases from one side of the cold metal (20) to the other. For example, the thickness of the cold metal may be formed thicker in the area where the cavity (10a) filled with the molten metal (40) is relatively thick to increase cooling capacity, and the thickness of the cold metal may decrease proportionally as it approaches the area where the cavity thickness decreases. Through this structure, a sudden temperature step difference that is prone to occur at the boundary of thickness change of the casting can be mitigated, and a gentle temperature gradient can be formed throughout the casting. Therefore, by applying such an inclined portion (25), bending deformation or hot tear of the casting caused by thermal stress that may occur during the solidification process can be suppressed.

[0056] Figure 7 is a control block diagram of the sand casting device shown in Figure 1.

[0057] Referring to FIG. 7, the sand casting device (1) may include a temperature sensor (200), a control unit (100), and a refrigerant control device (300).

[0058] A temperature sensor (200) is attached to the inside, side, or a point adjacent to the molten metal (40) of the cold metal (20) to detect temperature changes of the cold metal (20) occurring during the casting process. Data regarding the detected temperature value can be transmitted to the control unit (100).

[0059] The control unit (100) compares and analyzes real-time temperature data received from the temperature sensor (200) with a preset cooling speed. If the current temperature drop rate deviates from the target speed, the control unit (100) can control the refrigerant control device (300) to adjust the cooling speed.

[0060] The refrigerant control device (300) can control the flow rate, supply pressure, or flow rate of the refrigerant supplied to the cooling channel (24) according to a signal from the control unit (100). For example, if the temperature of the molten metal (40) drops slowly below a target value, the refrigerant control device (300) can increase the flow rate of the refrigerant in the cooling channel (24) to increase the heat absorption efficiency of the cold metal (20), thereby inducing stable solidification of the casting.

[0062] A sand casting apparatus according to one embodiment comprises: a mold (10) formed of molding sand and forming a cavity (10a) into which molten metal (40) can be filled; and a cold plate (20) disposed on one surface of the mold forming the cavity so as to be in direct contact with the molten metal, wherein the cold plate (20) is disposed at a position corresponding to a relatively thick portion of the casting to be formed within the cavity, and the cold plate may include a tapered shape that widens from one side to the other to increase the bonding strength with the molding sand.

[0063] The above cold metal may include a contact portion (21) that contacts the molding sand and the molten metal in the cavity; and a tapered portion (22) that is inclined so that the surface area widens from the contact portion toward the molding sand.

[0064] A sand casting device according to one embodiment may further include a gas discharge part (23) formed on the surface of the cold metal that contacts the molten metal so as to discharge gas.

[0065] A sand casting apparatus according to one embodiment may include a coating layer disposed on the contact surface of the cold metal with the molten metal, wherein the coating layer may include: a first coating layer (50a) which is in contact with the molten metal and is composed of a refractory material; and a second coating layer (50b) disposed between the cold metal and the first coating layer to control the heat transfer rate.

[0066] The above cold metal may include an inclined section (25) in which the thickness gradually changes from one side to the other in accordance with the thickness change of the casting.

[0067] It may further include a temperature sensor (200) attached to the above-mentioned cold metal to sense the temperature of the above-mentioned molten metal, a cooling channel (24) formed within the above-mentioned cold metal to allow the refrigerant to flow, and a control unit (100) that controls the flow rate of the refrigerant supplied to the cooling channel to correspond to a preset target cooling rate based on temperature data received from the temperature sensor.

[0068] The apparatus further includes a refrigerant control device (300) configured to control the flow rate of the refrigerant within the cooling channel, and the control unit (100) is configured to control the refrigerant control device based on the temperature data value.

[0069] Specific embodiments have been illustrated and described above. However, the invention is not limited to the embodiments described above, and those skilled in the art may make various modifications without departing from the essence of the technical concept of the invention as described in the following claims. Explanation of the symbols

[0071] 1: Sand casting device 2: Inlet 3: Spout 10: Mold 10a: Cavity 20: Cold Gold 21: Contact part 22: Tapered section 23: Gas exhaust part 24: Cooling Euro 25: Slope 30: Core 40: Molten metal 100: Control unit 200: Temperature sensor 300: Refrigerant control device

Claims

Claim 1 A sand casting apparatus comprising: a mold formed of casting sand and forming a cavity into which molten metal can be filled; a cooling element disposed on one surface of the mold forming the cavity so as to be in direct contact with the molten metal, wherein the cooling element is disposed at a position corresponding to a relatively thick portion of the casting to be formed within the cavity; a temperature sensor attached to the cooling element to sense the temperature of the molten metal; a cooling channel formed within the cooling element to allow a cooling element to flow; a control unit that controls the flow rate of the cooling element supplied to the cooling channel to correspond to a preset target cooling rate based on temperature data received from the temperature sensor; and a coating layer disposed on the contact surface of the cooling element with the molten metal, wherein the coating layer comprises: a first coating layer that is in contact with the molten metal and is composed of a refractory material; and a second coating layer disposed between the cooling element and the first coating layer to control the heat transfer rate. Claim 2 A sand casting apparatus according to claim 1, further comprising a refrigerant control device configured to control the flow rate of a refrigerant within the cooling channel, wherein the control unit is configured to control the refrigerant control device based on the temperature data. Claim 3 delete Claim 4 In claim 1, the above-mentioned cold metal is a sand casting apparatus comprising an inclined section in which the thickness gradually changes from one side to the other in accordance with the thickness change of the casting. Claim 5 In paragraph 4, a sand casting apparatus in which the thickness of the cold metal decreases as it goes from a relatively thick part of the cavity to a thin part.

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