Casting mold and casting method for automobile engine cylinder cover

Abstract

The invention provides an automobile engine cylinder cover casting mold and a casting method, and belongs to the technical field of engine cylinder cover casting, the automobile engine cylinder cover casting mold comprises a rack and a workbench arranged on the rack, the workbench is provided with a mold closing mechanism used for cylinder cover casting, and the mold closing mechanism comprises a bottom mold arranged on the workbench; the cooling mechanism is installed on the workbench and arranged below the bottom die, the cooling mechanism comprises a cooling cavity formed in the bottom of the bottom die, a sealing plate is arranged in the cooling cavity in a sliding mode, and a heat exchange cavity communicated with the cooling cavity is formed in the bottom of the bottom die; by arranging the heat exchange cavity and the partition plate mechanism which can be independently controlled, partitioned and time-sharing differential cooling of a thick-wall area and a thin-wall area of a casting is achieved. A strong temperature gradient from a thin wall to a thick wall is actively constructed, sequential solidification and feeding are effectively promoted, and the problems of internal shrinkage porosity, stress concentration and deformation caused by uneven cooling can be solved.

Description

Technical Field

[0001] This invention belongs to the field of engine cylinder head casting technology, specifically relating to an automobile engine cylinder head casting mold and casting method. Background Technology

[0002] The cylinder head of an automobile engine is a key component at the top of the engine. It seals the cylinders to form the combustion chamber and integrates complex structures such as intake and exhaust ports, water jackets, and oil passages. The cylinder head casting mold is a precision tooling used to produce this component. It is usually made of heat-resistant mold steel and includes a cavity, sand core, and cooling system. Molten aluminum alloy is injected into the mold under high pressure and cooled to form the cylinder head in one step.

[0003] Chinese patent CN113579165A discloses a casting structure and method for a vertical casting process of sand core assembly for diesel engine cylinder head assembly. The method includes two side tray cores; a lower water jacket core mounted on the two side tray cores; an exhaust manifold core seat mounted on the two side tray cores; an exhaust manifold core mounted on the two side tray cores and the exhaust manifold core seat; an intake manifold core mounted on the tray cores; an upper water jacket core mounted on the lower water jacket core; and a left top cover core and a right top cover core mounted on the two side tray cores respectively. The left and right top cover cores cooperate with the two side tray cores to form the shape of the cylinder head top surface. All sand cores are pressed together by a clamping device to form a sand core assembly casting structure. This allows for the molding of two cylinder heads at once, improving cylinder head dimensional accuracy, process yield, and internal cavity quality.

[0004] However, the above-mentioned technical solutions still have the following drawbacks. In engine cylinder head casting, especially when using advanced processes such as core assembly and vertical casting, although the accuracy of the sand core and the casting efficiency are improved, the cooling structure inside the mold is usually uniformly arranged, making it impossible to differentiate cooling for different wall thicknesses of the casting. The solidification process after casting the cylinder head cannot be precisely controlled, resulting in slow cooling in thick-walled areas, which easily leads to shrinkage porosity, and rapid cooling in thin-walled areas, which easily leads to deformation or white iron formation. This results in unstable internal quality of the casting, a high risk of deformation, and seriously affects casting quality and production efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a casting mold and casting method for automobile engine cylinder heads, aiming to solve the problem in the prior art that it is impossible to perform differentiated cooling on parts of different wall thicknesses of the casting during the cooling process of casting cylinder heads, resulting in unstable internal quality and easy deformation of the casting during cooling.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a casting mold for an automobile engine cylinder head, comprising: a frame and a worktable mounted on the frame, wherein a mold closing mechanism for cylinder head casting is mounted on the worktable, and the mold closing mechanism includes a bottom mold mounted on the worktable; The cooling mechanism is installed on the workbench and located below the bottom mold. The cooling mechanism includes a cooling cavity located at the bottom of the bottom mold, a sealing plate that is slidably installed inside the cooling cavity, a heat exchange cavity that communicates with the cooling cavity at the bottom of the bottom mold, multiple heat exchange cavities that are evenly arranged and located on the side of the cooling cavity close to the casting, a partition plate corresponding to the heat exchange cavity that is slidably installed inside the cooling cavity, a guide post that is installed at the bottom of the partition plate, a cooling plate that is slidably installed at the bottom of the sealing plate, the cooling plate that can drive some of the partition plates to move, and a support plate that is installed at the bottom of the cooling plate that can drive the remaining partition plates to move. An adjustment mechanism is provided on the cooling mechanism. The adjustment mechanism includes a reversing cylinder that is rotatably disposed on the outside of the guide column. A reversing assembly is provided on the reversing cylinder. The reversing assembly can control the rotation of the reversing cylinder and connect it to the cooling plate or support plate, thereby controlling the up and down movement of the guide column.

[0007] Its effect is that by integrating the cooling mechanism and the adjustment mechanism, it realizes the active and differentiated control of the cooling intensity and timing of different wall thickness areas of the cylinder head casting, solves the problems of shrinkage porosity, stress and deformation caused by uneven cooling in the existing technology, and significantly improves the casting quality and process stability.

[0008] A further technical solution of the present invention is that the guide post penetrates the sealing plate, the cooling plate and the support plate, the sealing plate is provided with a rubber gasket for sealing around its perimeter, the bottom mold is provided with a water inlet pipe and a water outlet pipe on both sides, the water inlet pipe and the water outlet pipe are located above the sealing plate and communicate with the cooling cavity, the heat exchange cavity has a cross-section in the shape of a boss that is smaller at the top and larger at the bottom, and the partition plate can seal the heat exchange cavity and completely separate it from the cooling cavity after contacting the heat exchange cavity.

[0009] Its effects are as follows: by setting up a boss-shaped heat exchange cavity and a sealable partition plate, the heat exchange area and coolant flow direction are optimized. Combined with the rubber seal of the sealing plate, the airtightness of the cooling cavity is ensured, effectively preventing cooling water leakage. It also realizes precise zoning control of the cooling channel, improving cooling efficiency and uniformity.

[0010] A further technical solution of the present invention is that the bottom of the workbench is provided with a first driving device capable of controlling the cooling plate to move up and down, the support plate is located below the closed plate and is fixedly connected to the closed plate, and the bottom of the workbench is provided with a second driving device capable of controlling the support plate to move up and down.

[0011] A further technical solution of the present invention is that the reversing assembly includes a first slot and a second slot disposed on the reversing cylinder. The first slot can contact and engage with the upper and lower surfaces of the cooling plate, and the second slot can contact and engage with the upper and lower surfaces of the support plate. The first slot and the second slot have the same structure and are respectively disposed on both sides of the reversing cylinder. A first guide groove is provided on the cooling plate to cooperate with the first slot. The first guide groove has the same shape as the first slot. A second guide groove is provided on the support plate to cooperate with the second slot. The second guide groove has the same shape as the first guide groove and is vertically aligned.

[0012] Its effects are as follows: the reversing component with slot and guide groove is easy to operate and can quickly adjust the cooling assignment of each heat exchange chamber, so that the same set of molds can flexibly adapt to the cooling requirements of cylinder heads with different internal structures, greatly improving the versatility of the mold.

[0013] A further technical solution of the present invention is that a fixing block is slidably provided at the bottom of the guide post, one end of the fixing block is connected to a first elastic element, the other end of the first elastic element is connected to the guide post, a limit block is provided on the side of the fixing block near the reversing cylinder, and a limit groove that cooperates with the limit block is provided on the reversing cylinder.

[0014] A further technical solution of the present invention is that a second elastic element is connected to the bottom of the partition plate, the other end of the second elastic element is connected to the guide post, a thermal expansion element is slidably arranged on the top of the partition plate, a third elastic element is connected to the bottom of the thermal expansion element, and the other end of the third elastic element is connected to the partition plate.

[0015] A further technical solution of the present invention is that the first elastic element, the second elastic element, and the third elastic element are configured as springs.

[0016] A further technical solution of the present invention is that a top mold is provided above the bottom mold, the bottom mold and the top mold are arranged in parallel, a first control component capable of driving the top mold to approach or move away from the bottom mold is installed on the top of the frame, a side mold is provided between the bottom mold and the top mold, the side mold is perpendicular to the bottom mold, a second control component capable of driving the side molds to approach or move away from each other is provided on the upper surface of the worktable, when the mold closing mechanism closes the mold, a mold cavity for pouring is formed, and an injection port for injecting liquid metal into the mold is provided on the top mold.

[0017] A method for casting an automobile engine cylinder head includes the following steps: S1. Place the matching sand core into the bottom mold, drive the top mold and side mold to close, forming a closed mold cavity, and pour high-temperature molten metal into the mold cavity through the injection port of the top mold to complete the cylinder head filling. S2. Cooling water is introduced into the cooling chamber, and heat is evenly exchanged through all heat exchange chambers to initially and gently cool the entire casting. S3. When the thin-walled area reaches the set temperature, the partition plate at the corresponding position moves and closes the heat exchange chamber, restricting the flow of cooling water and forming a static insulation layer. S4. If there is an area with excessively high temperature in the thin-walled region, the corresponding thermal expansion element expands, pushing the partition plate away from the heat exchange chamber, allowing cooling water to slowly enter and continue cooling the area until the thermal expansion element returns to its initial state. S5. Drive the support plate to move up, reduce the volume of the cooling chamber, and significantly increase the flow rate of cooling water flowing through the heat exchange chamber in the thick-walled area to implement enhanced cooling; S6. After the casting has solidified, stop cooling, open the mold closing mechanism, remove the casting and clean the casting and mold closing mechanism, and then prepare for the next cycle.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves differentiated cooling of the thick-walled and thin-walled regions of the casting by setting up independently controllable heat exchange chambers and partition plate mechanisms. After uniform cooling of the entire area in the early stage of solidification, it can automatically seal the flow channels in the thin-walled region to form a heat insulation layer, and simultaneously increase the cooling water flow rate in the thick-walled region, thereby actively constructing a strong temperature gradient from the thin-walled to the thick-walled region, effectively promoting sequential solidification and shrinkage compensation, and solving the problems of internal shrinkage porosity, stress concentration and deformation caused by uneven cooling.

[0019] 2. The adjustment mechanism of this invention, in conjunction with the thermal expansion element, enables the cooling system to adaptively adjust according to the actual temperature of the casting. The reversing assembly allows for flexible configuration of each heat exchange chamber to belong to either a thin-walled or thick-walled cooling group, achieving precise adaptation to cylinder heads with different structures. The thermal expansion element ensures that the thin-walled area automatically enters a heat preservation state after reaching the preset temperature, avoiding overcooling or insufficient cooling, and significantly improving the stability of casting quality and process adaptability. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present invention; Figure 2 This is a partial structural diagram of a specific embodiment of the present invention; Figure 3 This is a partial structural cross-sectional view of a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the cooling mechanism in a specific embodiment of the present invention; Figure 5 This is a partial front view of the cooling mechanism and the bottom mold in a specific embodiment of the present invention; Figure 6This is a schematic diagram of the bottom mold and heat exchange cavity in a specific embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the sealing plate, cooling plate, and support plate in a specific embodiment of the present invention; Figure 8 This is a schematic diagram of the installation of the adjusting mechanism and the guide column in a specific embodiment of the present invention; Figure 9 This is a schematic diagram of the adjustment mechanism in a specific embodiment of the present invention; Figure 10 This is a cross-sectional view of the adjusting mechanism in a specific embodiment of the present invention; Figure 11 This is a schematic diagram of the cooperative structure of the guide column, the partition plate, and the adjustment mechanism in a specific embodiment of the present invention.

[0021] In the diagram: 1. Frame; 11. First control component; 2. Workbench; 21. Second control component; 22. First drive device; 23. Second drive device; 3. Mold closing mechanism; 31. Bottom mold; 311. Water inlet pipe; 312. Water outlet pipe; 32. Top mold; 33. Side mold; 34. Heat exchange chamber; 4. Cooling mechanism; 41. Cooling chamber; 42. Enclosure plate; 43. Partition plate; 431. Guide post; 432. Second elastic element; 433. Thermal expansion element; 434. Third elastic element; 44. Cooling plate; 441. First guide groove; 45. Support plate; 451. Second guide groove; 5. Adjustment mechanism; 51. Reversing cylinder; 511. First slot; 512. Second slot; 513. Limiting groove; 52. Fixing block; 521. First elastic element; 522. Limiting block. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figures 1-11 The present invention provides the following technical solution: a casting mold for an automobile engine cylinder head, comprising a frame 1, a worktable 2, a mold closing mechanism 3, a cooling mechanism 4, and an adjustment mechanism 5.

[0024] The frame 1 is placed horizontally on the ground, and the workbench 2 is set on the frame 1. The workbench 2 is used to hold the casting mold. The mold closing mechanism 3 is set on the workbench 2. When casting the engine cylinder head, the sand core is first placed in the mold closing mechanism 3, and then the mold closing mechanism 3 is closed and sealed. After the mold closing mechanism 3 and the sand core are closed, they form the complex shape and internal cavity of the casting. After the mold closing mechanism is closed, the molten metal is poured into the mold closing mechanism 3 to cast the cylinder head structure. The cooling mechanism 4 is installed on the workbench 2 and is located below the mold closing mechanism 3. After the molten metal is poured into the mold closing mechanism 3, the cooling mechanism 4 cools and lowers the temperature of the molten metal. It can adjust the cooling time according to the wall thickness of different parts of the casting to prevent over-cooling of thin-walled areas and accelerate the solidification of thick-walled areas, thus shortening the solidification time of the casting. The adjustment mechanism 5 is set on the cooling mechanism 4. The adjustment mechanism 5 can adjust the distribution area of ​​the cooling mechanism 4, thereby adjusting the cooling control grouping of the corresponding thin-walled and thick-walled areas to adapt to the cooling requirements of cylinder heads with the same appearance but different internal structures, or the same cylinder head with different process schemes.

[0025] like Figures 1-3 As shown, the mold closing mechanism 3 includes a bottom mold 31 mounted on the workbench 2, and a top mold 32 disposed above the bottom mold 31. The bottom mold 31 and the top mold 32 are arranged in parallel. A first control component 11 is mounted on the top of the frame 1. The output end of the first control component 11 is connected to the side of the top mold 32 away from the bottom mold 31. The first control component 11 can drive the top mold 32 to move closer to or away from the bottom mold 31. A side mold 33 is disposed between the bottom mold 31 and the top mold 32. The side mold 33 is perpendicular to the bottom mold 31. In this embodiment, four side molds 33 are disposed. A second control component 21 is disposed on the upper surface of the workbench 2. The output end of the second control component 21 is connected to the side of the side mold 33 away from the bottom mold 31. The second control component 21 can drive the side molds 33 to move closer to or away from each other. When the top mold 32 and the side molds 33 move towards the bottom mold 31, they can dock and completely close together to form a mold cavity for casting an engine cylinder head. The top mold 32 has an injection port for injecting liquid metal into the mold.

[0026] During operation, a sand core that matches the engine cylinder head model is first placed on the upper surface of the bottom mold 31 to form the complex internal cavity and external shape of the cylinder head during casting. Then, the top mold 32 and the side mold 33 approach the bottom mold 31 and close completely to form a mold cavity for cylinder head forming. Then, molten metal is sent into the mold cavity through the injection port set on the top mold 32 to complete the casting of the engine cylinder head.

[0027] like Figures 3-9As shown, the cooling mechanism 4 includes a cooling cavity 41 located at the bottom of the bottom mold 31. A sealing plate 42 is slidably disposed inside the cooling cavity 41. The sealing plate 42 can slide up and down along the inside of the cooling cavity 41, approaching or moving away from the upper surface of the bottom mold 31 used for injection molding. Rubber gaskets are provided around the periphery of the sealing plate 42 to prevent poor sealing at the contact point between the sealing plate 42 and the inner wall of the cooling cavity 41 when the sealing plate 42 moves. Water inlet pipes 311 and water outlet pipes 312 are provided on both sides of the bottom mold 31. The water inlet pipes 311 and water outlet pipes 312 are located above the sealing plate 42 and communicate with the cooling cavity 41. After the cylinder head is cast, cooling water is introduced into the cooling cavity 41 through the water inlet pipe 311 to cool the formed casting. The cooling water, after heat exchange, is discharged from the water outlet pipe 312. The bottom of the bottom mold 31 is provided with a heat exchange cavity 34 that communicates with the cooling cavity 41. Multiple heat exchange cavities 34 are evenly arranged and located on the side of the cooling cavity 41 closest to the casting. The cross-section of the heat exchange cavity 34 is a boss-shaped structure, smaller at the top and larger at the bottom. The smaller top end face is close to the casting, and the larger bottom end face communicates with the cooling cavity 41. Due to the different thicknesses of the casting at different locations, different heat exchange cavities 34 correspond to castings of varying thicknesses. A partition plate 43 corresponding to the heat exchange cavity 34 is slidably arranged inside the cooling cavity 41. The partition plate 43 can move upwards and contact the bottom plane of the corresponding heat exchange cavity 34. When the partition plate 43 contacts the heat exchange cavity 34, it seals the heat exchange cavity 34 and completely separates it from the cooling cavity 41. A guide post 431 is provided at the bottom of the partition plate 43. The guide post 431 penetrates the sealing plate 42 and can move up and down relative to the sealing plate 42.

[0028] A cooling plate 44 is slidably mounted on the bottom of the sealing plate 42. Guide posts 431 are installed through the cooling plate 44. The cooling plate 44 can be connected to a portion of the guide posts 431, and the heat exchange chamber 34 corresponding to the top of this portion of the guide posts 431 is located at the bottom of the thinner casting. The cooling plate 44 can control the up-and-down movement of the connected guide posts 431. A first driving device 22 is installed at the bottom of the worktable 2. The output end of the first driving device 22 is connected to the bottom of the cooling plate 44. The first driving device 22 can control the up-and-down movement of the cooling plate 44. When the cooling plate 44 moves upward, it can control a portion of the partition plate 43 to move upward through the guide posts 431, thus sealing the heat exchange chamber 34 at the bottom of the thinner casting. A support plate 45 is slidably mounted on the bottom of the cooling plate 44. The support plate 45 is located below and fixedly connected to the sealing plate 42. Guide columns 431 are installed through the support plate 45. The remaining guide columns 431 not connected to the cooling plate 44 are all connected to the support plate 45. The support plate 45 can control the up and down movement of the remaining guide columns 431. A second drive device 23 is provided at the bottom of the worktable 2. The output end of the second drive device 23 is connected to the bottom of the support plate 45. The second drive device 23 can control the up and down movement of the support plate 45. When the support plate 45 moves upward, it can drive the sealing plate 42 and the remaining guide columns 431 to move upward synchronously and approach the casting.

[0029] After the engine cylinder head is cast, the casting needs to be cooled. At this time, cooling water is introduced into the cooling chamber 41 through the water inlet pipe 311. The cooling water evenly fills all the heat exchange chambers 34, and initially cools the high-temperature molten metal on the bottom mold 31. This can evenly reduce the overall temperature of the casting, avoid excessive thermal stress in any area due to rapid cooling, and form a uniform solidified shell on the surface of the casting during cooling. After the thinner areas of the casting have initially cooled and solidified, the cooling plate 44 is moved upward by the first drive device 22. At the same time, the guide column 431 corresponding to the bottom heat exchange chamber 34 of the thinner area of ​​the casting is moved upward until the partition plate 43 at the top of the guide column 431 contacts the heat exchange chamber 34, sealing the heat exchange chamber 34 and completely separating it from the cooling chamber 41. Some of the cooling water is then sealed in the heat exchange chamber 34. At this point, the cooling water inside the heat exchange chamber 34 corresponding to the thinner area of ​​the casting no longer flows. The static cooling water in this part absorbs the heat from the bottom mold 31 and its temperature rises, forming a relatively high-temperature buffer zone. This slows down the heat dissipation rate of the thin-walled area, prevents the area from continuously cooling rapidly, reduces thermal stress and the tendency for white cast iron, and at the same time slows down the solidification rate of the molten metal at this location, allowing the molten metal in the mold to flow to the location where the casting may shrink.

[0030] Because part of the heat exchange chamber 34 is closed, the internal volume of the cooling chamber 41 decreases. Under the premise that the total flow rate of cooling water remains unchanged, the flow rate of cooling water flowing through the remaining open heat exchange chamber 34 increases, accelerating the cooling of the thicker areas of the casting and causing its surface to solidify faster. Since the temperature of the mold in the thick-walled area is high, a vapor film that hinders heat exchange is easily generated. At this time, the second drive device 23 controls the support plate 45 to drive the closed plate 42 and the remaining guide columns 431 to move upward. During the upward movement of the closed plate 42, the space of the cooling chamber 41 is further reduced. Under the premise that the total flow rate of cooling water remains unchanged, its flow rate will increase sharply. The high-speed, high-turbulence cooling water can directly break up and carry away the vapor film, allowing the cold water to continuously and directly contact the high-temperature mold, maintaining extremely high heat exchange efficiency.

[0031] like Figure 4 and Figures 8-11As shown, the adjusting mechanism 5 includes a reversing cylinder 51 rotatably disposed outside the guide post 431, which can rotate along the axis of the guide post 431. A reversing assembly is provided on the reversing cylinder 51, which controls the connection between the reversing cylinder 51 and the cooling plate 44 or the support plate 45, thereby controlling the up-and-down movement of the guide post 431. The reversing assembly includes a first slot 511 disposed on one side of the reversing cylinder 51, which can contact and engage with the upper and lower surfaces of the cooling plate 44, causing the reversing cylinder 51 and the cooling plate 44 to move synchronously. The reversing assembly also includes a second slot 512 disposed on the other side of the reversing cylinder 51, which can contact and engage with the upper and lower surfaces of the support plate 45, thereby causing the reversing cylinder 51 and the support plate 45 to move synchronously. The first slot 511 and the second slot 512 have the same structure and are respectively disposed on both sides of the reversing cylinder 51. The cooling plate 44 has a first guide groove 441 that mates with the first slot 511. The first guide groove 441 and the first slot 511 have the same shape. When the reversing cylinder 51 rotates and aligns the first slot 511 with the first guide groove 441, the first slot 511 disengages from the cooling plate 44, and the reversing cylinder 51 can move up and down relative to the cooling plate 44. The support plate 45 has a second guide groove 451 that mates with the second slot 512. The second guide groove 451 and the first guide groove 441 have the same shape and are aligned vertically. A fixing block 52 is slidably disposed at the bottom of the guide post 431. The fixing block 52 can slide back and forth along the axial direction of the guide post 431. One end of the fixing block 52 is connected to a first elastic element 521, and the other end of the first elastic element 521 is connected to the guide post 431. In this embodiment, the first elastic element 521 is set as a spring. A limiting block 522 is provided on the side of the fixed block 52 near the reversing cylinder 51, and a limiting groove 513 is provided on the reversing cylinder 51 to cooperate with the limiting block 522. Initially, under the action of the first elastic member 521, the limiting block 522 is inserted into the limiting groove 513 and limits the reversing cylinder 51 to prevent it from rotating.

[0032] A second elastic element 432 is connected to the bottom of the partition plate 43, and the other end of the second elastic element 432 is connected to the guide post 431. When the partition plate 43 contacts the heat exchange chamber 34, it can compress the second elastic element 432, making the contact between the partition plate 43 and the heat exchange chamber 34 tighter. In this embodiment, the second elastic element 432 is set as a spring. A thermal expansion element 433 is slidably arranged on the top of the partition plate 43. The thermal expansion element 433 can slide up and down along the partition plate 43. In this embodiment, the thermal expansion element 433 is an aluminum-silicon alloy or a paraffin-based thermodynamic element, so that the thermal expansion element 433 can expand when a specific temperature is reached. The bottom of the thermal expansion element 433 is connected to a third elastic element 434, and the other end of the third elastic element 434 is connected to the partition plate 43. Through the pre-tightening force of the third elastic element 434, it is ensured that when the partition plate 43 contacts the heat exchange cavity 34, the top end of the thermal expansion element 433 can maintain contact with the inner wall of the heat exchange cavity 34 near the casting. At this time, the third elastic element 434 is deformed by force. In this embodiment, the third elastic element 434 is set as a spring.

[0033] Before casting the cylinder head, an adjustment mechanism 5 needs to be pre-configured. The worker first pulls the fixing block 52 away from the reversing cylinder 51, causing the limiting block 522 to disengage from the limiting groove 513. For the heat exchange cavity 34 corresponding to the thin-walled area of ​​the casting, the reversing cylinder 51 below it is rotated, causing the first slot 511 at this position to contact the upper and lower surfaces of the cooling plate 44. At this time, the reversing cylinder 51 can move synchronously with the cooling plate 44, and the second slot 512 on the reversing cylinder 51 rotates to the position corresponding to the second guide groove 451 and disengages from the support plate 45. Then, the fixing block 52 is released, and under the action of the first elastic element 521, the limiting block 522 is reinserted into the limiting groove 513, completing the positioning of the reversing cylinder 51. Subsequently, the reversing cylinder 51 below the heat exchange chamber 34 corresponding to the thicker part of the casting is rotated, and the second slot 512 at this position is rotated until it contacts the upper and lower surfaces of the support plate 45, so that the reversing cylinder 51 can move synchronously with the support plate 45. At this time, the first slot 511 on the reversing cylinder 51 is rotated to the position corresponding to the first guide groove 441 and disengages from the cooling plate 44. After fixing the positions of all reversing cylinders 51, cylinder head casting begins. By setting the reversing assembly, the cooling mechanism 4 can adapt to the cooling requirements of cylinder heads with the same appearance but different internal structures, achieving precise cooling of different parts.

[0034] In the initial cooling phase, as the partition plate 43 moves upward, the thermal expansion element 433 corresponding to the thinner section first contacts the inner wall of the heat exchange chamber 34. When the casting at this position has cooled to the set temperature of the thermal expansion element 433, the size of the thermal expansion element 433 remains unchanged. If the temperature at this position exceeds the set temperature, the thermal expansion element 433 begins to expand due to heat. At this time, the partition plate 43 begins to move away from the casting under pressure, while compressing the second elastic element 432, and the partition plate 43 begins to disengage from the heat exchange chamber 34. At this time, low-temperature cooling water can enter the interior of the heat exchange chamber 34 and continue to accelerate the cooling of the casting until the casting at this position cools to the set temperature. Subsequently, the thermal expansion element 433 begins to contract to its initial state, and the partition plate 43 contacts the heat exchange chamber 34 again under the action of the second elastic element 432. Setting the thermal expansion element 433 can avoid uneven thickness in some thinner areas of the casting corresponding to the heat exchange chamber 34, which would cause temperature differences when the partition plate 43 closes the area, resulting in uneven cooling temperature. Furthermore, because the openings of the partition plate 43 when it is no longer in contact with the heat exchange chamber 34 are relatively small, these locations can prevent a large amount of cooling water from filling the interior of the heat exchange chamber 34, thus avoiding localized overcooling at these locations.

[0035] Once the thicker areas of the casting have cooled to the set temperature and solidified, the cooling mechanism 4 stops working, the mold closing mechanism 3 is opened, and the casting is removed for further processing. The mold closing mechanism 3 is then cleaned, and preparation is made for the next cylinder head casting operation.

[0036] A method for casting an automobile engine cylinder head includes the following steps: S1. Place the matching sand core into the bottom mold 31, drive the top mold 32 and the side mold 33 to close, forming a closed mold cavity, and pour high-temperature molten metal into the mold cavity through the injection port of the top mold 32 to complete the cylinder head filling. S2. Cooling water is introduced into the cooling chamber 41 and heat is evenly exchanged through all heat exchange chambers 34 to initially and gently cool the entire casting. S3. When the thin-walled area reaches the set temperature, the partition plate 43 at the corresponding position moves and closes the heat exchange chamber 34, restricting the flow of cooling water and forming a static insulation layer. S4. If there is an overheated area in the thin-walled region of the casting, the corresponding thermal expansion element 433 expands, pushing the partition plate 43 away from the heat exchange chamber 34, allowing cooling water to slowly enter the area and continue to cool it until the thermal expansion element 433 returns to its initial state. S5. Drive the support plate 45 to move upward, reduce the volume of the cooling chamber 41, and significantly increase the flow rate of the cooling water flowing through the heat exchange chamber 34 in the thick-walled area to implement enhanced cooling. S6. After the casting has solidified, stop cooling, open the mold closing mechanism 3, remove the casting and clean the casting and mold closing mechanism 3, and then prepare for the next cycle.

Claims

1. A casting mold for an automobile engine cylinder head, comprising: A frame (1) and a worktable (2) provided on the frame (1), wherein a mold closing mechanism (3) for cylinder head casting is provided on the worktable (2), characterized in that the mold closing mechanism (3) includes a bottom mold (31) provided on the worktable (2). Cooling mechanism (4) is installed on workbench (2) and located below bottom mold (31). Cooling mechanism (4) includes a cooling cavity (41) located at the bottom of bottom mold (31). A sealing plate (42) is slidably arranged inside the cooling cavity (41). A heat exchange cavity (34) communicating with the cooling cavity (41) is provided at the bottom of bottom mold (31). Multiple sets of heat exchange cavities (34) are evenly arranged and located on the side of cooling cavity (41) close to the casting. A partition plate (43) corresponding to the heat exchange cavity (34) is slidably arranged inside the cooling cavity (41). A guide column (431) is provided at the bottom of the partition plate (43). A cooling plate (44) is slidably arranged at the bottom of the sealing plate (42). The cooling plate (44) can drive some partition plates (43) to move. A support plate (45) is provided at the bottom of the cooling plate (44). The support plate (45) can drive the remaining partition plates (43) to move. Adjustment mechanism (5) is provided on cooling mechanism (4). Adjustment mechanism (5) includes a reversing cylinder (51) rotatably provided on the outside of guide column (431). Reversing assembly is provided on reversing cylinder (51). Reversing assembly can control reversing cylinder (51) to rotate and connect with cooling plate (44) or support plate (45), thereby controlling guide column (431) to move up and down.

2. The automobile engine cylinder head casting mold according to claim 1, characterized in that: The guide post (431) passes through the sealing plate (42), the cooling plate (44) and the support plate (45). The sealing plate (42) is provided with a rubber pad for sealing. The bottom mold (31) is provided with a water inlet pipe (311) and a water outlet pipe (312) on both sides. The water inlet pipe (311) and the water outlet pipe (312) are located above the sealing plate (42) and are connected to the cooling chamber (41). The heat exchange chamber (34) has a cross-section that is smaller at the top and larger at the bottom in the shape of a boss. After the partition plate (43) comes into contact with the heat exchange chamber (34), it can seal the heat exchange chamber (34) and completely separate it from the cooling chamber (41).

3. The automobile engine cylinder head casting mold according to claim 2, characterized in that: The bottom of the workbench (2) is provided with a first drive device (22) that can control the cooling plate (44) to move up and down. The support plate (45) is located below the closed plate (42) and is fixedly connected to the closed plate (42). The bottom of the workbench (2) is provided with a second drive device (23) that can control the support plate (45) to move up and down.

4. The automobile engine cylinder head casting mold according to claim 3, characterized in that: The reversing assembly includes a first slot (511) and a second slot (512) disposed on the reversing cylinder (51). The first slot (511) can contact and engage with the upper and lower surfaces of the cooling plate (44), and the second slot (512) can contact and engage with the upper and lower surfaces of the support plate (45). The first slot (511) and the second slot (512) have the same structure and are respectively disposed on both sides of the reversing cylinder (51). The cooling plate (44) is provided with a first guide groove (441) that cooperates with the first slot (511). The first guide groove (441) has the same shape as the first slot (511). The support plate (45) is provided with a second guide groove (451) that cooperates with the second slot (512). The second guide groove (451) has the same shape as the first guide groove (441) and is aligned vertically.

5. The automobile engine cylinder head casting mold according to claim 4, characterized in that: A fixing block (52) is slidably provided at the bottom of the guide post (431). One end of the fixing block (52) is connected to a first elastic element (521), and the other end of the first elastic element (521) is connected to the guide post (431). A limit block (522) is provided on the side of the fixing block (52) near the reversing cylinder (51), and a limit groove (513) is provided on the reversing cylinder (51) to cooperate with the limit block (522).

6. The automobile engine cylinder head casting mold according to claim 5, characterized in that: The bottom of the partition plate (43) is connected to a second elastic element (432), the other end of the second elastic element (432) is connected to a guide post (431), a thermal expansion element (433) is slidably provided on the top of the partition plate (43), a third elastic element (434) is connected to the bottom of the thermal expansion element (433), and the other end of the third elastic element (434) is connected to the partition plate (43).

7. The automobile engine cylinder head casting mold according to claim 6, characterized in that: The first elastic element (521), the second elastic element (432) and the third elastic element (434) are configured as springs.

8. The automobile engine cylinder head casting mold according to claim 7, characterized in that: A top mold (32) is provided above the bottom mold (31). The bottom mold (31) and the top mold (32) are arranged in parallel. A first control component (11) capable of driving the top mold (32) to approach or move away from the bottom mold (31) is installed on the top of the frame (1). A side mold (33) is provided between the bottom mold (31) and the top mold (32). The side mold (33) is perpendicular to the bottom mold (31). A second control component (21) capable of driving the side molds (33) to approach or move away from each other is provided on the upper surface of the worktable (2). When the mold closing mechanism (3) closes the mold, a mold cavity for pouring is formed. A liquid injection port for injecting liquid metal into the mold is provided on the top mold (32).

9. A method for casting an automobile engine cylinder head, characterized in that: The method of using the automotive engine cylinder head casting mold as described in claim 8 includes the following steps: S1. Place the matching sand core into the bottom mold (31), drive the top mold (32) and the side mold (33) to close together to form a closed mold cavity, and pour high-temperature molten metal into the mold cavity through the injection port of the top mold (32) to complete the cylinder head filling. S2. Cooling water is introduced into the cooling chamber (41) and heat is evenly exchanged through all heat exchange chambers (34) to initially and gently cool the entire casting. S3. When the thin-walled area reaches the set temperature, the partition plate (43) at the corresponding position moves and closes the heat exchange chamber (34), restricting the flow of cooling water and forming a static insulation layer. S4. If there is a location with excessively high temperature in the thin-walled area, the corresponding thermal expansion element (433) expands, pushing the partition plate (43) away from the heat exchange chamber (34), allowing cooling water to slowly enter the location and continue to cool the location until the thermal expansion element (433) returns to its initial state. S5. Drive the support plate (45) to move upward, reduce the volume of the cooling chamber (41), greatly increase the flow rate of cooling water flowing through the heat exchange chamber (34) in the thick wall area, and implement enhanced cooling; S6. After the casting has solidified, stop cooling, open the mold closing mechanism (3), take out the casting and clean the casting and the mold closing mechanism (3), and then prepare for the next cycle.

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