Special-shaped chilling block structure for strong chilling and rapid preparation method

Abstract

The invention relates to the technical field of casting, and discloses a special-shaped chilling block structure for strong chilling and a rapid preparation method.The special-shaped chilling block structure for strong chilling comprises a chilling block body, imbedding connecting pieces are arranged on the two sides of the bottom of the chilling block body, and the imbedding connecting pieces are of hollow structures; an inverted-U-shaped cooling through hole is formed in the portion, between the two imbedding connecting pieces, of the chilling block body. The chilling block body is of a fan-shaped structure, the multiple chilling block bodies form a ring, the interior of the ring is assembled on a sand core, and the surface of the ring is used for chilling of a casting special-shaped structure. The method has the advantages that a thin sand shell only needs to be replicated and printed, low-cost resin sand is used for filling and molding after rapid assembly, and production can be achieved through pouring, due to the fact that most of expensive printing sand materials are replaced with the low-cost resin sand, the manufacturing cost is low, the method has the advantages of 3D printing manufacturing accuracy and short period, and the method is suitable for large-scale popularization and application. The method is suitable for mass production.

Description

Technical Field

[0001] The invention relates to the technical field of casting, and in particular to a special-shaped chilled iron structure for strong chilling and a rapid preparation method thereof. Background Art

[0002] In the casting process, it is often necessary to set a chiller body at an appropriate position of the casting to cooperate with the riser to control the solidification order of the casting, improve the shrinkage compensation efficiency of the riser, prevent shrinkage cavities and shrinkage porosity in the casting, and improve the density of the casting; in addition, the use of the chiller body can accelerate the local cooling rate of the casting, eliminate local thermal stress to prevent deformation and cracks; and accelerate the cooling rate of certain special parts of the casting, refine the matrix structure, and improve the mechanical properties of the casting. In the thick and large parts of the casting, due to the influence of the heat storage capacity of the chiller, the chiller will no longer continue to absorb heat after it is saturated, and the chiller's cooling effect will be greatly reduced.

[0003] 3D printing sand molds use additive manufacturing technology and are laid layer by layer according to the designed sand mold model. Sand molds produced using 3D printing technology are not restricted by shape and can print any shape except closed cavities. However, 3D printing sand molds can only be made of one material and cannot directly set metal bodies during the sand mold printing process.

[0004] When chillers are mass-produced, conventional chiller production modes include: 1. Processing and molding (large batches, special-shaped parts consume more machine tool hours, with high production costs and long construction periods); 2. Mold sand casting (this method first requires the manufacture of more solid models, and then molding. For this type of chiller body with a special-shaped air duct in the middle, mold manufacturing is more troublesome and the construction period is longer); 3. Conventional 3D direct printing of the chiller body shape requires the sand mold shape to be modified, which will destroy the accuracy. Conventional methods are to print the outer shell, assemble it after molding, and then assemble the core inside. It also requires printing a large amount of sand, which consumes a lot of sand, and the mold is not accurate, which is easy to cause displacement and causes the shape of the chiller body to be inaccurate, and the cost is expensive.

[0005] Therefore, the above problems are solved by a special-shaped chiller structure for strong quenching and a rapid preparation method. Summary of the invention

[0006] The object of the present invention is to provide a special-shaped chiller structure for strong quenching and a rapid preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: comprising a chiller body, wherein both sides of the bottom of the chiller body are provided with cast-in connectors, the cast-in connectors are hollow structures, and an inverted U-shaped cooling through hole is provided on the chiller body between the two cast-in connectors; The chill body is a fan-shaped structure. There are multiple chill bodies, and the multiple structures form a ring. The inside of the ring is assembled with a sand core and the surface is used for chilling the special-shaped structure of the casting.

[0008] Preferably, the cast-in connector includes a first connector and a second connector, the top end of the second connector is located inside the first connector, the top end of the first connector is a first fitting surface, the inner circumferential surface of the second connector is a first locking surface, the first connector and the second connector are integrally formed, a first positioning boss is provided on the bottom edge of the first connector, and the cast-in connector is formed by copper alloy.

[0009] A method for quickly preparing a special-shaped chilled iron structure for strong quenching, comprising a sand shell bottom plate for molding a chilled iron body and a molding sand shell arranged above the sand shell bottom plate, wherein a chilled iron molding cavity consistent with the outer structure of the chilled iron body is provided inside the molding sand shell, second positioning grooves are provided on both sides of the bottom end of the molding sand shell, and two second positioning bosses are provided above the sand shell bottom plate to cooperate with the second positioning grooves at the bottom of the molding sand shell. The molding sand shell and the sand shell bottom plate are manufactured by 3D printing.

[0010] Preferably, a mounting hole for mounting the cast-in connector is provided above the sand shell bottom plate, the mounting hole is a stepped hole, a first positioning groove cooperating with a first positioning boss at the bottom of the first connector is provided on the stepped portion, and the bottom end of the first connector contacts the top end of the stepped portion of the mounting hole.

[0011] Preferably, a cooling air duct sand core having the same structure as the cooling through hole is installed between the two first connecting members, and the cooling air duct sand core is manufactured by 3D printing.

[0012] Preferably, the preparation method comprises the following steps: Step 1: first install the cast-in connector in the mounting hole of the sand shell bottom plate. During installation, ensure that the first positioning boss is installed in cooperation with the first positioning groove to achieve positioning, and at the same time ensure that the bottom end of the first connector is in contact with the top end of the step portion of the mounting hole; Step 2: Install the 3D printed cooling air duct sand core in the cast connector. During installation, ensure that the outer side of the cooling air duct sand core end is in contact with the first contact surface of the first connector, and ensure that the end of the cooling air duct sand core is in contact with the first locking surface of the second connector. Then install the molded sand shell on top of the sand shell bottom plate. During installation, the second positioning groove and the second positioning boss cooperate to achieve positioning. Step 3: Arrange the assembled sand molds in order, fill them with sand, and after the mold is removed and the pouring system is poured, an inner gate is opened on the outer arc at the bottom of the molding sand shell to complete the molding; Step 4: After smelting, cast and form the chilled iron body; Step 5: After removing the cooling airway sand core, sand shell bottom plate and molding sand shell by vibration, the chiller body with cast-in connectors and cooling through holes can be obtained.

[0013] Technical effects and advantages of the present invention: The present invention adopts 3D printing technology to manufacture cold iron of any complex shape. The manufacturing process only needs to replicate and print a thin layer of sand shell, which can be quickly assembled and filled with cheap resin sand for casting and production. Since the cheap resin sand replaces most of the expensive printing sand materials, the manufacturing cost is low, and it has the advantages of 3D printing manufacturing accuracy and short cycle, which is suitable for mass production. 2. The chiller body of the present invention is made of cast aluminum material, because aluminum has a faster thermal conductivity than steel, so it can quickly absorb the heat of thick and large parts and conduct it away. The material of the inlay casting connector is processed copper parts, which has a high melting point and can be well inlaid with the chiller body during casting, and it also has a high thermal conductivity. 3. One end of the cast-in connector of the present invention is directly cast in the chiller body, and the other end is connected to the external air pipe, one is connected as an air inlet, and the other is connected as an air outlet. The gas adopts high-pressure and low-temperature gas, which is automatically sprayed in through the air inlet and out through the air outlet. The rapid spraying increases the flow rate, continuously and quickly takes away the absorbed heat, and the chilling effect of the chiller body is strong and lasting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the cold iron body in the present invention.

[0015] Figure 2 It is a cross-sectional view of the cold iron body in the present invention.

[0016] Figure 3 It is a schematic diagram of the structure of the cast-in connector in the present invention.

[0017] Figure 4 It is a schematic diagram of the sand shell bottom plate structure of the present invention.

[0018] Figure 5 It is a schematic diagram of the installation structure of the sand shell bottom plate and the cast-in connector of the present invention.

[0019] Figure 6 It is a schematic diagram of the structure of the sand shell bottom plate, the cast-in connector and the cooling airway sand core in the present invention.

[0020] Figure 7 It is a schematic diagram of the internal cavity structure of the molded sand shell in the present invention.

[0021] Figure 8 It is a structural diagram of the chiller body sand mold after assembly in the present invention.

[0022] Fig. 9It is a schematic diagram of the assembly and use of the chiller body and the sand core in the present invention.

[0023] In the figure: 1. cold iron body; 101. cooling through hole; 2. cast-in connector; 201. first connector; 202. second connector; 203. first positioning boss; 204. first fitting surface; 205. first locking surface; 3. molding sand shell; 301. second positioning groove; 4. sand shell bottom plate; 401. mounting hole; 402. first positioning groove; 403. second positioning boss; 5. cooling airway sand core; 6. sand core. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] In the casting process, it is often necessary to set a chiller body at an appropriate position of the casting to cooperate with the riser to control the solidification order of the casting, improve the shrinkage compensation efficiency of the riser, prevent shrinkage cavities and shrinkage porosity in the casting, and improve the density of the casting; in addition, the use of the chiller body can accelerate the local cooling rate of the casting, eliminate local thermal stress to prevent deformation and cracks; and accelerate the cooling rate of certain special parts of the casting, refine the matrix structure, and improve the mechanical properties of the casting. In the thick and large parts of the casting, due to the influence of the heat storage capacity of the chiller, the chiller will no longer continue to absorb heat after it is saturated, and the chiller's cooling effect will be greatly reduced.

[0026] 3D printing sand molds use additive manufacturing technology and are laid layer by layer according to the designed sand mold model. Sand molds produced using 3D printing technology are not restricted by shape and can print any shape except closed cavities. However, 3D printing sand molds can only be made of one material and cannot directly set metal bodies during the sand mold printing process.

[0027] When chillers are mass-produced, conventional chiller production modes include: 1. Processing and molding (large batches, special-shaped parts consume more machine tool hours, with high production costs and long construction periods); 2. Mold sand casting (this method first requires the manufacture of more solid models, and then molding. For this type of chiller body with a special-shaped air duct in the middle, mold manufacturing is more troublesome and the construction period is longer); 3. Conventional 3D direct printing of the chiller body shape requires the sand mold shape to be modified, which will destroy the accuracy. Conventional methods are to print the outer shell, assemble it after molding, and then assemble the core inside. It also requires printing a large amount of sand, which consumes a lot of sand, and the mold is not accurate, which is easy to cause displacement and causes the shape of the chiller body to be inaccurate, and the cost is expensive.

[0028] The present invention provides Figures 1 to 9 The illustrated special-shaped chiller structure for strong quenching comprises a chiller body 1, with cast-in connectors 2 provided on both sides of the bottom of the chiller body 1, the cast-in connectors 2 being hollow structures, and an inverted U-shaped cooling through hole 101 provided on the chiller body 1 between the two cast-in connectors 2; The chiller body 1 is a fan-shaped structure. There are multiple chiller bodies 1, and the multiple structures form a ring. The sand core 6 is assembled inside the ring and the surface is used for quenching the special-shaped structure of the casting. The chiller body 1 is made of cast aluminum.

[0029] Among them, the cast-in connector 2 includes a first connector 201 and a second connector 202, the top end of the second connector 202 is located inside the first connector 201, the inner circle of the first connector 201 is a first fitting surface 204, the top end of the second connector 202 is a first locking surface 205, the first connector 201 and the second connector 202 are integrally formed, and a first positioning boss 203 is provided on the bottom edge of the first connector 201. The cast-in connector 2 is formed by copper alloy.

[0030] A method for quickly preparing a special-shaped cold iron structure for strong quenching, comprising a sand shell bottom plate 4 for forming a cold iron body 1 and a forming sand shell 3 arranged above the sand shell bottom plate 4, a cold iron forming cavity consistent with the outer structure of the cold iron body 1 is opened inside the forming sand shell 3, second positioning grooves 301 are opened on both sides of the bottom end of the forming sand shell 3, two second positioning bosses 403 cooperating with the second positioning grooves 301 at the bottom of the forming sand shell 3 are opened above the sand shell bottom plate 4, and the forming sand shell 3 and the sand shell bottom plate 4 are made by 3D printing.

[0031] Among them, a mounting hole 401 for mounting the cast-in connector 2 is opened above the sand shell bottom plate 4, and the mounting hole 401 is a stepped hole. The stepped portion is opened with a first positioning groove 402 that cooperates with the first positioning boss 203 at the bottom of the first connector 201. The bottom end of the first connector 201 contacts the top of the stepped portion of the mounting hole 401 to prevent the cast-in connector 2 from rotating inside the mounting hole 401, thereby ensuring the stability of the cast-in connector 2 when in use.

[0032] A cooling air duct sand core 5 having the same structure as the cooling through hole 101 is installed between the two first connecting members 201 , and the cooling air duct sand core 5 is manufactured by 3D printing.

[0033] Wherein, the preparation method comprises the following steps: Step 1: Figure 4 and 5As shown, the cast-in connector 2 is first installed in the mounting hole 401 of the sand shell bottom plate 4. During installation, ensure that the first positioning boss 203 is installed in cooperation with the first positioning groove 402 to achieve positioning, and ensure that the bottom end of the first connector 201 is in contact with the top end of the step portion of the mounting hole 401; Step 2: Figure 6-8 As shown, the 3D printed cooling air duct sand core 5 is installed in the cast connector 2. During installation, ensure that the outer side of the end of the cooling air duct sand core 5 is in contact with the first fitting surface 204 of the first connector 201, and ensure that the end of the cooling air duct sand core 5 is in contact with the first locking surface 205 of the second connector 202. Then, the molding sand shell 3 is installed above the sand shell bottom plate 4. During installation, the second positioning groove 301 and the second positioning boss 403 are used to cooperate to achieve positioning. Step 3: Arrange the assembled sand molds in order, fill them with sand, and after the mold is removed and the pouring system is cast, an inner gate is opened on the outer arc at the bottom of the molding sand shell 3 to complete the molding; Step 4: After smelting, casting and forming the chilled iron body 1; Step 5: After removing the cooling airway sand core 5, the sand shell bottom plate 4 and the forming sand shell 3 by shaking, the chiller body 1 with the cast-in connector 2 and the cooling through hole 101 can be obtained.

[0034] When using, Fig. 9 As shown, the chill body 1 is formed into a circular structure and assembled around the outer periphery of the sand core 6. After the assembly is completed, the cast connector 2 is sequentially inserted into the core head through hole reserved in the sand mold process, the sand core 6 is fixed, the box is closed and locked, and the first connector 201 and the second connector 202 are connected to the external circulating gas path from the bottom of the sand mold, waiting for pouring. During pouring, the chill body 1 can be continuously circulated and quickly cooled by external circulating water or cooling gas. When this chill is needed in large quantities, the conventional chill production modes are: 1. Processing and molding (large quantities, special-shaped parts consume more machine tools) Hours, high production cost and long construction period); 2. Mold sand casting (this method first requires the manufacture of more solid models, and then the shaping. For this kind of cold iron body with a special-shaped air duct in the middle, mold manufacturing is more troublesome and the construction period is longer); 3. Conventional 3D direct printing of the cold iron body shape requires the sand mold shape to be modified, which will destroy the accuracy. Conventional methods are to print the outer shell, assemble it after molding, and then assemble the core inside. It also requires printing more sand, which consumes more sand, and the mold is not accurate, which is easy to cause the shape of the cold iron body to be inaccurate and expensive.

[0035] When in use, the chiller body 1 is made of cast aluminum material. Since aluminum has a faster thermal conductivity than steel, it can quickly absorb heat from thick and large parts and conduct it away. The cast-in connector 2 is made of processed copper. Copper has a high melting point and can be well cast with the chiller body 1 during casting. It also has a high thermal conductivity.

[0036] One end of the cast-in connector 2 is directly cast in the chiller body 1, and the other end is connected to the external air pipe, one is connected as an air inlet, and the other is connected as an air outlet. The gas uses high-pressure and low-temperature gas, which is automatically sprayed in at the air inlet and out at the air outlet. The rapid spray increases the flow rate, takes away the quickly absorbed heat, and enhances the quenching effect of the chiller body 1.

[0037] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A special-shaped chiller structure for strong chilling, characterized in that: It comprises a chiller body (1), wherein cast-in connectors (2) are provided on both sides of the bottom of the chiller body (1), the cast-in connectors (2) are hollow structures, and an inverted U-shaped cooling through hole (101) is provided on the chiller body (1) between the two cast-in connectors (2); The chiller body (1) is a fan-shaped structure. There are multiple chiller bodies (1), and the multiple structures form a ring. The sand core (6) is assembled inside the ring, and the surface is used for quenching the special-shaped structure of the casting.

2. The special-shaped chiller structure for strong chilling according to claim 1, characterized in that: The cast-in connector (2) comprises a first connector (201) and a second connector (202), the top end of the second connector (202) being located inside the first connector (201), the inner circle of the first connector (201) being a first fitting surface (204), the top end of the second connector (202) being a first locking surface (205), the first connector (201) and the second connector (202) being integrally formed, and a first positioning boss (203) being provided at the bottom edge of the first connector (201).

3. A method for quickly preparing a special-shaped cold iron structure for strong quenching, which is applied to a special-shaped cold iron structure for strong quenching as described in any one of claims 1 to 2, comprising the sand shell bottom plate (4) for forming a cold iron body (1) and the forming sand shell (3) arranged above the sand shell bottom plate (4), a cold iron forming cavity consistent with the outer structure of the cold iron body (1) is opened inside the forming sand shell (3), second positioning grooves (301) are opened on both sides of the bottom end of the forming sand shell (3), and two second positioning bosses (403) are opened above the sand shell bottom plate (4) to cooperate with the second positioning grooves (301) at the bottom of the forming sand shell (3).

4. The method for rapidly preparing a special-shaped chilled iron structure for strong chilling according to claim 3, characterized in that: A mounting hole (401) for mounting the cast-in connector (2) is provided above the sand shell bottom plate (4); the mounting hole (401) is a stepped hole, a first positioning groove (402) cooperating with a first positioning boss (203) at the bottom of the first connector (201) is provided at the stepped portion, and the bottom end of the first connector (201) contacts the top end of the stepped portion of the mounting hole (401).

5. A method for rapidly preparing a special-shaped chilled iron structure for strong chilling according to claim 4, characterized in that: A cooling air duct sand core (5) having the same structure as the cooling through hole (101) is installed between the two first connecting members (201), and the cooling air duct sand core (5) is manufactured by 3D printing.

6. A method for rapidly preparing a special-shaped chiller structure for strong chilling, the method being implemented by using a special-shaped chiller structure for strong chilling as claimed in any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step 1: first install the cast-in connector (2) in the mounting hole (401) of the sand shell bottom plate (4). During installation, ensure that the first positioning boss (203) is installed in cooperation with the first positioning groove (402) to achieve positioning, and ensure that the bottom end of the first connector (201) is in contact with the top end of the step portion of the mounting hole (401); Step 2: Install the 3D printed cooling air duct sand core (5) in the cast connector (2). During installation, ensure that the outer side of the end of the cooling air duct sand core (5) is in contact with the first contact surface (204) of the first connector (201), and ensure that the end of the cooling air duct sand core (5) is in contact with the first locking surface (205) of the second connector (202). Then, install the molded sand shell (3) above the sand shell bottom plate (4). During installation, the second positioning groove (301) and the second positioning boss (403) cooperate to achieve positioning. Step 3: Arrange the assembled sand molds in order, fill them with sand and shape them. After removing the mold and pouring the system, open an inner gate on the outer arc at the bottom of the molding sand shell (3) to complete the molding; Step 4: After smelting, casting is performed to form a chilled iron body (1); Step 5: After removing the cooling airway sand core (5), the sand shell bottom plate (4) and the forming sand shell (3) by shaking, a chiller body (1) with an inlaid cast connector (2) and a cooling through hole (101) can be obtained.

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