Sand mold structure for automotive engine cylinder block casting

Abstract

This invention discloses a sand mold structure for casting automotive engine cylinder blocks in the field of sand casting technology. It includes a sand mold body, a cylinder block forming cavity, a gating system, and a flow-blocking unit. The cylinder block forming cavity is located in the core area of ​​the sand mold body. The flow-blocking unit is positioned between the gating system and the cylinder block forming cavity, and the gating system is precisely connected to the cylinder block forming cavity through the flow-blocking unit. By adding the flow-blocking unit, this invention immediately cuts off the metal flow channel after filling, preventing the high-temperature metal in the gating system from continuously conducting heat to the hot spots of the cylinder block. This ensures that the cylinder block cools according to a preset directional solidification logic, completely solving the problems of shrinkage cavities and porosity in thick-walled and mounting areas of the cylinder block. Simultaneously, it effectively prevents the secondary backflow of slag, oxide scale, low-temperature cold metal, and gas in the gating system, eliminating slag inclusions, porosity, and other defects. This significantly improves the internal density and structural strength of the engine cylinder block, meeting the requirements for precision components.

Description

Technical Field

[0001] This invention relates to the field of sand casting technology, and in particular to a sand mold structure for casting automobile engine cylinder blocks. Background Technology

[0002] The cylinder block of an automobile engine is a core heavy-duty precision component. It has a complex structure, uneven wall thickness, and concentrated heat points. It is required to be free of defects such as shrinkage cavities, porosity, air holes, and slag inclusions. It also has extremely high requirements for dimensional accuracy and structural strength. Currently, the industry generally uses sand casting process for mass production.

[0003] In existing traditional cylinder casting sand mold structures, the gating system's sprue, runner, ingate, and cylinder cavity are an integrated, interconnected structure. After the molten metal fills the mold, the gating system and the casting body maintain a complete metal flow channel without any immediate isolation structure. This structure has several inherent defects in actual production: After filling, the high-temperature molten metal in the gating system continuously transfers heat to the hot spots of the cylinder, disrupting the directional solidification logic. This leads to shrinkage cavities and porosity defects in thick-walled parts of the cylinder, reducing sealing performance and structural strength, resulting in a high scrap rate. During solidification shrinkage, cold metal, slag, and oxide scale in the gating system easily flow back, causing defects such as slag inclusions and porosity, affecting the cylinder assembly accuracy and service life. The traditional thick-walled gate cleaning process is cumbersome and inefficient, easily causing cylinder annealing and cracks. Residual roots require additional processing, increasing costs and losses. The gate is easily washed away and stuck with sand by high-temperature erosion, resulting in a short sand mold life and cylinder deformation and dimensional deviations. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention proposes a sand mold structure for casting automobile engine cylinder blocks to solve such problems.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a sand mold structure for casting automobile engine cylinder blocks, including a sand mold body, a cylinder block forming cavity, a gating system, and a flow-blocking unit. The cylinder block forming cavity is located in the core area of ​​the sand mold body, and the flow-blocking unit is disposed between the gating system and the cylinder block forming cavity. The gating system is precisely connected to the cylinder block forming cavity through the flow-blocking unit.

[0006] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the flow-cutting and isolation unit includes a connecting component connected between the gating system and the cylinder block forming cavity, a limiting component fixedly connected to the lower end of the connecting component, multiple sets of annularly equally distributed cutting components on the limiting component, a driving component sleeved on the upper end of the connecting component and with its lower end in contact with the top surface of the limiting component, the outer end of the cutting component extending upward into the driving component, and a cylinder fixedly connected to the side of the limiting component, with the outer end of the cylinder connected to the driving component.

[0007] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the connecting component includes a connecting pipe with a circular tubular structure, and a limiting component is fixedly sleeved on the lower end of the connecting pipe, while the driving component rotates on the connecting pipe, a limiting ring is set on the outer wall of the connecting pipe, and multiple sets of connecting ports equally opened on the lower end outer wall of the connecting pipe.

[0008] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the limiting component includes a limiting seat fixedly connected to the lower end of the connecting pipe, and the bottom surface of the driving component is in contact with the bottom surface of the limiting seat, multiple sets of limiting grooves equally divided on the top surface of the limiting seat, and multiple sets of cutting components correspondingly installed in the multiple sets of limiting grooves, and a mounting bracket provided on the side of the limiting seat, and one end of the cylinder is rotatably connected to the mounting bracket.

[0009] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the limiting groove is a rectangular groove structure with a side opening, and one side of the limiting groove opening is connected to the inside of the connecting pipe. At the same time, the number and position of the limiting grooves correspond one-to-one with the connection ports.

[0010] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the cutting component includes a partition plate slidably connected in a limiting groove, an extension shaft disposed at the outer end of the partition plate and extending upward into the drive component, a protrusion disposed on one side of the partition plate, and a groove opened on the other side of the partition plate and matching the size of the protrusion.

[0011] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the separator plate is generally triangular in shape, with its outer end being rectangular, and the separator plate is horizontally slidably connected to the limiting groove through the outer end of the rectangle.

[0012] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the separator is made of ceramic material, the outer wall of the ceramic material is rough and does not easily adhere to molten metal, and the bottom surface of the separator has a sloping structure that curves from the outside to the inside.

[0013] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, the driving component includes a driving disc sleeved on a connecting pipe, multiple sets of driving grooves equally distributed around the driving disc, and the driving grooves are generally arc-shaped. The arc-shaped structure is inclined from the edge of the driving disc to its center and extends upward into the driving groove. A fixed shaft is provided on the driving disc, and the outer end of the cylinder is rotatably connected to the fixed shaft.

[0014] As a preferred embodiment of the automobile engine cylinder block casting sand mold structure of the present invention, wherein: a sealing component is installed in the limiting groove, the sealing component includes a receiving groove opened below the opening position of the limiting groove, a partition inserted into the receiving groove, and the partition completely closes the opening position of the limiting groove, while the top of the partition has an inclined structure, and a spring is provided at the lower end of the partition.

[0015] The beneficial effects of this invention are as follows: By adding a flow-blocking unit, the metal flow channel is immediately cut off after the filling is completed, blocking the continuous heat conduction from the high-temperature metal in the gating to the hot spots of the cylinder block, ensuring that the cylinder block cools according to the preset directional solidification logic, and completely solving the problems of shrinkage cavities and porosity in the thick-walled parts and mounting parts of the cylinder block; at the same time, it effectively prevents the secondary backflow of slag, oxide scale, low-temperature cold metal and gas in the gating, eliminates slag inclusions, porosity and impurity defects, significantly improves the internal density and structural strength of the engine cylinder block, and meets the requirements of precision parts. The flow cut-off unit can avoid the long-term high temperature accumulation at the root of the gate, which will cause thermal stress concentration and effectively prevent thermal cracks and warping deformation in thin-walled and corner positions of the cylinder. At the same time, it can remove the constraint of the runner metal on the cylinder shrinkage, ensure uniform cooling and shrinkage of the casting, significantly reduce the probability of dimensional deviation and deformation scrap, and improve the assembly accuracy of the cylinder. The flow cut-off unit can also reduce the long-term scouring of the sand mold at the gate by the high-temperature molten metal, reduce the risk of sand washing and sticking, extend the service life of the sand mold, and reduce sand mold loss; the gating and casting are separated cleanly without residual metal nodules, and the waste material of the gating can be recycled and remelted in a unified manner, without additional metal waste, improving the utilization rate of metal raw materials and reducing production energy consumption. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the flow-blocking isolation unit of the automobile engine cylinder block casting sand mold structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the open state of the flow-blocking isolation unit of the automobile engine cylinder block casting sand mold structure of the present invention.

[0018] Figure 3 This is an exploded view of the structure of the flow-blocking isolation unit of the automobile engine cylinder block casting sand mold structure of the present invention.

[0019] Figure 4 This is a schematic diagram of the cross-sectional structure of the sand mold flow-blocking unit for casting automobile engine cylinder blocks according to the present invention.

[0020] Figure 5 This is a schematic diagram of the structure of the sand mold structure cut-off component for casting automobile engine cylinder blocks according to the present invention.

[0021] Figure 6 This is a schematic diagram of the structure of the sand mold sealing component for automobile engine cylinder block of the present invention.

[0022] Reference numerals: 1. Connecting component; 11. Connecting pipe; 12. Limiting ring; 13. Connection port; 2. Limiting component; 21. Limiting seat; 22. Limiting groove; 23. Mounting bracket; 3. Cut-off component; 31. Separator; 32. Extension shaft; 33. Protrusion; 34. Groove; 4. Driving component; 41. Driving disc; 42. Driving groove; 43. Fixed shaft; 5. Cylinder; 6. Sealing component; 61. Receiving groove; 62. Partition; 63. Spring; 7. Sprue. Detailed Implementation

[0023] To make the above-mentioned objectives, features and advantages of the present invention more readily understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] Reference Figures 1 to 6 This invention provides an embodiment of a sand mold structure for casting an automotive engine cylinder block, comprising a sand mold body, a cylinder block forming cavity, a gating system, and a flow-blocking unit. The cylinder block forming cavity is located in the central core area of ​​the sand mold body. The flow-blocking unit is positioned between the gating system and the cylinder block forming cavity, and the gating system is precisely connected to the cylinder block forming cavity through the flow-blocking unit. The sand mold structure, the cylinder block forming cavity, and the gating system are all mature structures in the prior art, and their shapes and specific structural compositions can be referenced from the prior art.

[0026] Reference Figure 3The flow-blocking unit includes a connecting component 1 connected between the gating system and the cylinder forming cavity, a limiting component 2 fixedly connected to the lower end of the connecting component 1, multiple sets of annularly equally distributed cutting components 3 on the limiting component 2, a driving component 4 sleeved on the upper end of the connecting component 1 and with its lower end abutting against the top surface of the limiting component 2, with the outer end of the cutting component 3 extending upward into the driving component 4, and a cylinder 5 fixedly connected to the side of the limiting component 2, with the outer end of the cylinder 5 connected to the driving component 4. When in use, the connecting component 1 is connected between the gating system and the cylinder forming cavity and remains stationary, while the driving component 4 can rotate around the connecting component 1 as an axis under the push of the cylinder 5.

[0027] Reference Figure 3 The connecting component 1 includes a cylindrical connecting pipe 11, and a limiting component 2 is fixedly sleeved on the lower end of the connecting pipe 11. At the same time, the driving component 4 rotates on the connecting pipe 11. A limiting ring 12 is set on the outer wall of the connecting pipe 11, and multiple sets of connecting ports 13 are equally distributed on the lower end outer wall of the connecting pipe 11. The hollow interior of the connecting pipe 11 can form a gating channel 7 for casting molten metal. By controlling the on / off state of the gating channel 7, the operation of cutting off or conveying molten metal can be realized.

[0028] Reference Figure 3 The limiting component 2 includes a limiting seat 21 fixedly connected to the lower end of the connecting pipe 11, and the bottom surface of the driving component 4 is in contact with the bottom surface of the limiting seat 21. Multiple sets of limiting grooves 22 are equally spaced on the top surface of the limiting seat 21, and multiple sets of cutting components 3 are correspondingly installed in the multiple sets of limiting grooves 22. A mounting bracket 23 is provided on the side of the limiting seat 21, and one end of the cylinder 5 is rotatably connected to the mounting bracket 23. The limiting grooves 22 are used to install the limiting cutting components 3, so that the cutting components 3 can only move in a specified direction under the limitation of the limiting grooves 22.

[0029] Reference Figure 3 The limiting groove 22 has a rectangular groove structure with a side opening, and one side of the opening of the limiting groove 22 is connected to the inside of the connecting pipe 11. At the same time, the number and position of the limiting groove 22 correspond one-to-one with the connection port 13. The limiting groove 22 and the connection port 13 cooperate with each other to form a channel for the limiting cut-off component 3 to move.

[0030] Reference Figure 5The cutting component 3 includes a partition plate 31 slidably connected in the limiting groove 22, an extension shaft 32 disposed at the outer end of the partition plate 31 and extending upward into the drive component 4, a protrusion 33 disposed on one side of the partition plate 31, and a groove 34 opened on the other side of the partition plate 31 and matching the size of the protrusion 33. The cutting component 3 can be driven by the drive component 4 through the extension shaft 32. The structural design of the protrusion 33 and the groove 34 can effectively prevent vertical gaps from appearing at the joint between each pair of adjacent cutting components 3 during the cutting operation, thereby effectively preventing molten metal from flowing downward through the gaps and causing problems such as gate wire drawing and unevenness.

[0031] Reference Figure 5 The separator 31 has a triangular structure as a whole, and its outer end has a rectangular structure. The separator 31 is horizontally slidably connected to the limiting groove 22 through the outer end of the rectangle. The separator 31, through its special structure, can only slide horizontally within the limiting groove 22.

[0032] Reference Figure 4 and Figure 5 The separator 31 is made of ceramic material. Ceramic material not only has a rough outer wall and is not easy to adhere to molten metal, but also has excellent high temperature resistance. It can maintain a stable shape in high temperature casting environment and will not crack due to sudden temperature changes. It has strong chemical stability and will not react with molten metal, ensuring the purity of the cast product. At the same time, it has high mechanical strength and can withstand various pressures and impacts during the casting process. The bottom surface of the separator 31 has a sloping structure that rises from the outside to the inside. During the circumferential cutting operation, this sloping structure can guide the molten metal to flow smoothly and reduce the residue at the gate.

[0033] Reference Figure 3 The driving component 4 includes a driving disk 41 sleeved on the connecting pipe 11, multiple sets of driving grooves 42 evenly distributed around the driving disk 41, and the driving grooves 42 are generally arc-shaped. The arc-shaped structure is inclined from the edge of the driving disk 41 to its center. The extension shaft 32 extends upward into the driving groove 42, and a fixed shaft 43 is set on the driving disk 41. The outer end of the cylinder 5 is rotatably connected to the fixed shaft 43. The driving component 4 can rotate around the connecting pipe 11 as the axis through the extension and retraction of the cylinder 5. The rotating driving disk 41 can push the extension shaft 32 through the driving grooves 42. The pushed extension shaft 32 will change its position in the horizontal direction under the operation of the arc angle structure of the driving groove 42, thereby realizing the function of pushing the cutting component 3 to move in the horizontal direction.

[0034] Reference Figure 6A sealing component 6 is installed in the limiting groove 22. The sealing component 6 includes a storage groove 61 opened below the opening of the limiting groove 22, a partition 62 inserted into the storage groove 61, and the partition 62 completely seals the opening of the limiting groove 22. The top of the partition 62 is inclined, and a spring 63 is set at the lower end of the partition 62. The spring 63 can always push the partition 62 upward through its own elastic support. The size of the partition 62 matches the opening size of the limiting groove 22. Therefore, the upwardly pushed partition 62 can seal the opening of the limiting groove 22, thereby effectively preventing molten metal from entering the limiting groove 22 when idle. Furthermore, the inclined structure at the top of the partition 62 can, through its cooperation with the inclined edge of the bottom surface of the partition 31, convert the force of the partition 31 moving outward into the force that pushes the partition 62 downward into the receiving groove 61 when the partition 31 is pushed outward by the driving component 4, thereby ensuring the normal outward extension of the partition 31.

[0035] During use, combined with Figure 1 and Figure 2In its normal state, the multiple sets of slit components 3 are retracted within their respective limiting grooves 22. At this time, the gating system is in the open state. Subsequently, the gating system transports the molten metal through the connecting pipe 11 to the forming cavity of the sand mold body. After the molten metal is transported, the cylinder 5 is instantly activated to extend and retract. The extended cylinder 5 pushes the drive component 4 to rotate around the connecting pipe 11. The rotating drive component 4 pushes the extension shaft 32 through the drive groove 42, causing the separator 31 to extend from the limiting groove 22. The multiple sets of slit components 3... Extending inwards, the molten metal will converge from multiple circumferential positions and ultimately cut off the flow of molten metal in the gating system 7. Furthermore, multiple sets of cutting components 3 will cooperate to form a disc-shaped barrier structure, further blocking the flow of molten metal. In summary, the extension of the multiple sets of cutting components 3 can be achieved simply by extending and retracting the cylinder 5, resulting in extremely fast cutting operation and instantaneous cutting. By adding a flow-intercepting unit, the metal flow channel is immediately cut off after filling, blocking the high flow of the gating system. The warm metal continuously conducts heat to the hot spots of the cylinder block, ensuring that the cylinder block cools according to the preset directional solidification logic, completely solving the problems of shrinkage cavities and porosity in thick-walled and mounting parts of the cylinder block; at the same time, it effectively prevents the secondary backflow of slag, oxide scale, low-temperature cold metal and gas in the gating system, eliminating defects such as slag inclusions, porosity and impurities, significantly improving the internal density and structural strength of the engine cylinder block, meeting the requirements of precision components; the flow-blocking unit can also prevent the long-term high temperature accumulation at the root of the gate, which will cause thermal stress concentration, effectively preventing the cylinder block from thin-walled and corner areas. Hot cracks and warping deformation may occur; at the same time, the constraint of the metal in the gating 7 on the shrinkage of the cylinder body is removed, ensuring uniform cooling and shrinkage of the casting, greatly reducing the probability of dimensional deviations and deformation scrap, and improving the assembly accuracy of the cylinder body; the flow cut-off unit can also reduce the long-term scouring of the sand mold at the gate by the high-temperature molten metal, reduce the risk of sand washing and sticking, extend the service life of the sand mold, and reduce sand mold loss; the gating 7 is cleanly separated from the casting without residual metal nodules, and the waste material in the gating can be uniformly recycled and remelted, without additional metal waste, improving the utilization rate of metal raw materials and reducing production energy consumption.

[0036] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A sand mold structure for casting automobile engine cylinder blocks, comprising a sand mold body, a cylinder block forming cavity, a gating system, and a flow cut-off unit, characterized in that: The cylinder forming cavity is located in the core area of ​​the sand mold body. The flow interception unit is set between the casting system and the cylinder forming cavity, and the casting system is precisely connected to the cylinder forming cavity through the flow interception unit.

2. The sand mold structure for casting automobile engine cylinder blocks according to claim 1, characterized in that: The flow-blocking unit includes a connecting component (1) connected between the casting system and the cylinder forming cavity, a limiting component (2) fixedly connected to the lower end of the connecting component (1), multiple sets of cut-off components (3) evenly arranged in annular shape on the limiting component (2), a driving component (4) sleeved on the upper end of the connecting component (1) and with its lower end in contact with the top surface of the limiting component (2), with the outer end of the cut-off component (3) extending upward into the driving component (4), and a cylinder (5) fixedly connected to the side of the limiting component (2), with the outer end of the cylinder (5) connected to the driving component (4).

3. The sand mold structure for casting automobile engine cylinder blocks according to claim 2, characterized in that: The connecting component (1) includes a connecting pipe (11) with a cylindrical structure, and a limiting component (2) is fixedly sleeved on the lower end of the connecting pipe (11). At the same time, the driving component (4) rotates on the connecting pipe (11), a limiting ring (12) is set on the outer wall of the connecting pipe (11), and multiple sets of connecting ports (13) are equally opened on the lower end of the outer wall of the connecting pipe (11).

4. The sand mold structure for casting automobile engine cylinder blocks according to claim 2 or 3, characterized in that: The limiting component (2) includes a limiting seat (21) fixedly connected to the lower end of the connecting pipe (11), and the bottom surface of the driving component (4) is in contact with the bottom surface of the limiting seat (21), multiple sets of limiting grooves (22) equally divided on the top surface of the limiting seat (21), multiple sets of cutting components (3) correspondingly installed in the multiple sets of limiting grooves (22), and a mounting bracket (23) set on the side of the limiting seat (21), and one end of the cylinder (5) is rotatably connected to the mounting bracket (23).

5. The sand casting structure for automobile engine cylinder blocks according to claim 4, characterized in that: The limiting groove (22) is a rectangular groove structure with a side opening, and one side of the opening of the limiting groove (22) is connected to the inside of the connecting pipe (11). At the same time, the number and position of the limiting groove (22) correspond one-to-one with the connection port (13).

6. The sand casting structure for automobile engine cylinder blocks according to claim 4, characterized in that: The cutting component (3) includes a partition plate (31) slidably connected in the limiting groove (22), an extension shaft (32) disposed at the outer end of the partition plate (31) and the extension shaft (32) extending upward into the drive component (4), a protrusion (33) disposed on one side of the partition plate (31), and a groove (34) opened on the other side of the partition plate (31) and matching the size of the protrusion (33).

7. The sand casting structure for automobile engine cylinder blocks according to claim 6, characterized in that: The separator (31) has a triangular structure as a whole, and its outer end has a rectangular structure. The separator (31) is horizontally slidably connected to the limiting groove (22) through the outer end of the rectangle.

8. The sand casting structure for automobile engine cylinder blocks according to claim 7, characterized in that: The separator (31) is made of ceramic material. The outer wall of the ceramic material is rough and does not easily adhere to the molten metal. The bottom surface of the separator (31) has a sloping structure that curves from the outside to the inside.

9. The sand casting structure for automobile engine cylinder blocks according to claim 4, characterized in that: The drive component (4) includes a drive disk (41) sleeved on the connecting pipe (11), multiple sets of drive grooves (42) evenly arranged around the drive disk (41), and the drive grooves (42) are arc-shaped in whole. The arc-shaped structure is inclined from the edge of the drive disk (41) to its center position. The extension shaft (32) extends upward into the drive groove (42), and a fixed shaft (43) is set on the drive disk (41). The outer end of the cylinder (5) is rotatably connected to the fixed shaft (43).

10. The sand mold structure for casting automobile engine cylinder blocks according to claim 4, characterized in that: A sealing component (6) is installed in the limiting groove (22). The sealing component (6) includes a storage groove (61) opened below the opening of the limiting groove (22), a partition (62) inserted into the storage groove (61), and the partition (62) completely seals the opening of the limiting groove (22). At the same time, the top of the partition (62) is inclined, and a spring (63) is set at the lower end of the partition (62).

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