Low-pressure casting mold for large aluminum alloy auxiliary frame

Abstract

The invention discloses a low-pressure casting mold for a large aluminum alloy auxiliary frame, relates to the technical field of aluminum alloy casting, and aims to solve the technical problems that a mold core structure of a current mold often needs to be manually demolded, the demolding difficulty is high, and the production efficiency is low. By arranging the variable mold core, when the variable mold core is in the stretching state, the first linear deformation structure and the bending deformation structure extend, the second linear deformation structure synchronously stretches, the mold core framework is constructed, the elastic sleeve is supported, and therefore the mold core is formed, and in the casting process, the mold core assists in forming the hollow front beam and the hollow rear beam of the auxiliary frame; and when casting is completed and a demolding stage is entered, the variable mold core is switched to a contraction state, and each structure rapidly contracts and becomes short and is separated from a casting hole reserved in the partition plate. When the auxiliary frame with the hollow front beam and the hollow rear beam is produced, the demolding difficulty is greatly reduced, the demolding efficiency is improved, and efficient production of the auxiliary frame is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy casting, and more specifically, to a low-pressure casting mold for a large aluminum alloy subframe. Background Art

[0002] Aluminum alloy subframes play a crucial role in the field of automobile manufacturing. Since their mass can be reduced by 30% - 50% compared to traditional steel subframes, they can effectively reduce the weight of the entire vehicle, thereby improving fuel economy or extending the driving range of electric vehicles. They are made through precision casting processes, and their structural design needs to consider both strength and lightweight. During vehicle driving, the aluminum alloy subframe bears and transmits various forces from the road surface, including the forces generated during acceleration, braking, and steering, providing stable support for the vehicle chassis system and ensuring the vehicle's handling performance.

[0003] In existing large aluminum alloy subframes, due to their large volume, in order to further reduce the weight of the subframe and save costs, the front and rear beam frames are set as hollow structures. At the same time, in order to enhance the structural strength of the front and rear beam frames, bending parts are provided on the front and rear beam frames, thereby increasing the strength of the subframe in multiple directions.

[0004] However, the core structures of existing molds are mostly fixed structures, which are difficult to flexibly adapt to the complex shaping requirements of the hollow front and rear beams. When producing subframes with hollow front and rear beams, during the demolding stage, the core and the casting will be closely adhered and difficult to separate. Workers often need to use a large number of tools and spend a lot of time manually operating to complete demolding. Not only is the demolding extremely difficult, but it is also extremely easy to cause damage such as scratches and deformation to the casting, seriously affecting the product quality. The cumbersome demolding process greatly extends the production cycle, resulting in low production efficiency. In view of this, we propose a low-pressure casting mold for a large aluminum alloy subframe. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art, adapt to the actual needs, and provide a low-pressure casting mold for a large aluminum alloy subframe to solve the technical problems that the core structure of the current mold often requires manual demolding, with high demolding difficulty and low production efficiency.

[0006] To solve the above technical problems, the present invention provides the following technical solution: A low-pressure casting mold for a large aluminum alloy subframe, including an upper mold and a lower mold, and two variable cores are connected to the bottom end of the upper mold; The variable core has an extended state and a contracted state, and includes two first linear deformation structures, two bending deformation structures, and a second linear deformation structure; in the extended state, the first linear deformation structure and the bending deformation structure connected thereto extend and elongate, the second linear deformation structure extends and elongates, and both ends are respectively attached to one end of the two bending deformation structures, and are used as the skeletons of the cores in the upper mold and the lower mold to assist in casting the hollow front and rear beams of the subframe; in the contracted state, the first linear deformation structure and the bending deformation structure connected thereto contract and shorten, and the second linear deformation structure contracts and shortens, and is used for demolding after casting the hollow front and rear beams of the subframe. Three air inlets are respectively connected to the two first linear deformation structures and the second linear deformation structure, and the air inlets communicate with an external air inlet pump. A partition is installed at the air inlets, and elastic sleeves are sleeved on the first linear deformation structure and the bending deformation structure, and another elastic sleeve is sleeved on the second linear deformation structure.

[0007] Preferably, the widths of the two partitions are greater than the length of the first linear deformation structure and the bending deformation structure in the contracted state, and the width of the other partition is greater than the length of the second linear deformation structure in the contracted state.

[0008] Preferably, the upper mold and the lower mold are provided with mold cavities, and the mold cavities and the variable core in the extended state sleeved with an elastic sleeve form a subframe forming structure for casting the subframe.

[0009] Preferably, the first linear deformation structure includes a first end block, a first elastic cable, a first support frame, and a connecting frame; The four first elastic cables are installed at the four corners of the first end block, the other ends of the four first elastic cables are installed at the four corners of the connecting frame, the four first elastic cables penetrate and are connected at the four corners of a plurality of first support frames, the plurality of first support frames are arranged equidistantly inside the elastic sleeve, and the outer sides of the first support frames are attached to the inner wall of the elastic sleeve.

[0010] Preferably, the bending deformation structure includes a support beam, a connecting rod, and a connecting cable; The connecting rod is a shape memory metal. When a plurality of the support beams and a plurality of the connecting rods extend, a bent and extended structure is formed, and the adjacent two sets of bent and extended structures are connected by a connecting cable to form a bending deformation skeleton. The two bending deformation skeletons are respectively installed at the top end and the bottom end of one side of the connecting frame. A connecting rod is slidably connected between two adjacent support beams, and a plurality of connecting rods are arranged in a stepped manner on the plurality of support beams.

[0011] Preferably, the second linear deformation structure includes a second end block, a second elastic cable, and a second support frame; The four second elastic cords are connected to the four corners of the two second end blocks, and the four second elastic cords penetrate and are connected to the four corners of a number of second support frames. The number of the second support frames are arranged equidistantly inside the elastic sleeve, and the outer sides of the second support frames are attached to the inner wall of the elastic sleeve.

[0012] Preferably, second adsorption blocks are installed at the four corners of the second end block. The second adsorption blocks are adsorption-connected to first adsorption blocks, and the four first adsorption blocks are respectively connected to the four corners of the outer elastic sleeve of the bending deformation skeleton.

[0013] Preferably, the air inlet is also communicated with a cooling structure and an external air conditioner, and the three cooling structures are respectively arranged in the two first linear deformation structures and the second linear deformation structure. The cooling structure includes an intake pipe and a connecting hose; A number of the intake pipes are respectively connected to the first support frame or the second support frame. The number of the intake pipes are connected to each other through the connecting hose, and the end intake pipe is communicated to the variable core.

[0014] Preferably, the variable core is connected to an air outlet, the air outlet is communicated to an external air extraction pump, and electric control valves are arranged on both the air intake pump and the air extraction pump.

[0015] Preferably, a number of vertical forming parts are equidistantly arranged along the long axis direction on both sides of the elastic sleeve. The forming parts are S-shaped structures, and inner grooves are arranged on the inner sides of the forming parts. A number of horizontal contraction grooves are equidistantly arranged along the long axis direction at the top and bottom of the elastic sleeve. The contraction grooves are V-shaped structures, and the larger opening ends of the V-shaped structures face the inner side of the elastic sleeve.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. By providing a variable core, when the variable core is in the extended state, the first linear deformation structure and the bending deformation structure extend, and the second linear deformation structure extends synchronously to construct a core skeleton and support the elastic sleeve, thereby forming a core. During the casting process, this core assists in forming the hollow front and rear beams of the subframe. When the casting is completed and enters the demolding stage, the variable core switches to the contracted state, and each structure quickly contracts and shortens, separating from the casting holes reserved by the partition. The present invention can greatly reduce the demolding difficulty, accelerate the demolding efficiency, and ensure the efficient production of the subframe when producing a subframe with hollow front and rear beams.

[0017] 2. Through the cooling structure, during demolding, the air conditioner flows low-temperature gas along the air inlet, and through the intake pipe and connecting hose, it flows through each support frame, achieving all-round cooling of the core through the support frame. The air outlet is connected to the upper mold air outlet pipe, and the gas is discharged by opening the electric control valve. After the casting is cooled to the demolding temperature, it is easier for the casting to separate from the core. The present invention can reduce the demolding resistance through the cooling structure, avoid demolding damage, and improve the qualified product rate.

[0018] 3. By providing a forming part with an S-shaped structure, when the elastic sleeve is filled with gas, the forming part can be pushed outwards by the gas through the inner groove, thereby forming an S-shaped strengthening groove inside the subframe during casting, and enhancing the structural strength of the subframe through the strengthening groove. Through the S-shaped forming part, the present invention can form a strengthening groove structure on the inner wall of the subframe during casting, thereby increasing the structural strength of the subframe.

[0019] 4. By providing a V-shaped shrinkage groove, when the elastic sleeve shrinks, the V-shaped shrinkage groove becomes the starting point of deformation and bends first, enabling the elastic sleeve to easily shrink and deform and quickly fold together. By providing the V-shaped shrinkage groove, the present invention accelerates the shrinkage process of the elastic sleeve and shortens the time required for deformation and demolding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the present invention when the variable core is removed.

[0021] Figure 2 It is a schematic structural diagram of the upper mold of the present invention.

[0022] Figure 3 It is a schematic structural diagram of the lower mold of the present invention.

[0023] Figure 4 It is a schematic structural diagram of the present invention when the upper mold is connected to the variable core.

[0024] Figure 5 It is a schematic structural diagram of the extended state of the variable core of the present invention.

[0025] Figure 6 It is a schematic cross-sectional structural diagram of the extended state of the variable core of the present invention.

[0026] Figure 7 It is a schematic internal structural diagram of the extended state of the first linear deformation structure and the bending deformation structure of the present invention.

[0027] Figure 8 It is a schematic structural diagram of the contracted state of the first linear deformation structure and the bending deformation structure of the present invention.

[0028] Figure 9 It is a schematic structural diagram of the contracted state of the second linear deformation structure of the present invention.

[0029] Figure 10 This is a schematic cross-sectional view of the first linear deformation structure and the bending deformation structure of the present invention in a contracted state.

[0030] Figure 11 This is a schematic cross-sectional view of the second linear deformation structure of the present invention in a contracted state.

[0031] Figure 12 This is a schematic structural view of the aluminum alloy subframe produced by the present invention when the variable core is not demolded.

[0032] Figure 13 This is a schematic structural view of the aluminum alloy subframe produced by the present invention.

[0033] Figure 14 This is a schematic cross-sectional view of the elastic sleeve of the present invention.

[0034] Explanation of the reference numerals in the figure: 1. Upper die; 2. Lower die; 3. Variable core; 4. Air inlet; 5. Air outlet; 6. Mold cavity; 301. First linear deformation structure; 302. Bending deformation structure; 303. Second linear deformation structure; 304. Partition; 305. Elastic sleeve; 306. Cooling structure; 3011. First end block; 3012. First elastic cord; 3013. First support frame; 3014. Connection frame; 3021. Support beam; 3022. Connecting rod; 3023. Connecting cord; 3024. First adsorption block; 3031. Second end block; 3032. Second elastic cord; 3033. Second support frame; 3034. Second adsorption block; 3051. Forming part; 3052. Shrinkage groove; 3061. Inlet pipe; 3062. Connecting hose. Detailed implementation manner

[0035] Example: As Figures 1 to 9 shown, a low-pressure casting mold for a large aluminum alloy subframe according to the present invention includes an upper die 1 and a lower die 2. Two variable cores 3 are connected to the bottom end of the upper die 1. A mold cavity 6 is provided between the upper die 1 and the lower die 2. The mold cavity 6 and the variable core 3 with an elastic sleeve 305 in an extended state form a subframe forming structure for casting the subframe.

[0036] The variable core 3 has an extended state and a contracted state, and includes two first linear deformation structures 301, two bending deformation structures 302, and a second linear deformation structure 303; in the extended state, the first linear deformation structure 301 and the bending deformation structure 302 connected thereto extend, the second linear deformation structure 303 extends, and both ends are respectively attached to one end of the two bending deformation structures 302, and are used as the skeleton of the core in the upper mold 1 and the lower mold 2 to assist in casting the hollow front and rear beams of the subframe; in the contracted state, the first linear deformation structure 301 and the bending deformation structure 302 connected thereto contract and become shorter, and the second linear deformation structure 303 contracts and becomes shorter, and is used for demolding after casting the hollow front and rear beams of the subframe.

[0037] Three air inlets 4 are respectively connected to the two first linear deformation structures 301 and the second linear deformation structure 303, and the air inlets 4 are communicated with an external air inlet pump. A partition 304 is installed at the air inlets 4. An elastic sleeve 305 is sleeved on the first linear deformation structure 301 and the bending deformation structure 302, and another elastic sleeve 305 is sleeved on the second linear deformation structure 303. The elastic sleeve 305 can be made of heat-resistant and elastic rubber material.

[0038] In the present invention, by providing a variable core 3, when the variable core 3 is in the extended state, the first linear deformation structure 301 and the bending deformation structure 302 extend, and the second linear deformation structure 303 extends synchronously to construct a core skeleton and support the elastic sleeve 305, thereby forming a core. During the casting process, this core assists in forming the hollow front and rear beams of the subframe; and when the casting is completed and enters the demolding stage, the variable core 3 switches to the contracted state, and each structure quickly contracts and becomes shorter, and separates from the casting holes reserved by the partition 304. The present invention can greatly reduce the demolding difficulty, accelerate the demolding efficiency, and ensure the efficient production of the subframe when producing a subframe with hollow front and rear beams.

[0039] Specifically, as Figure 5 and Figure 12 shown, the widths of the two partitions 304 involved in the present invention are greater than the lengths of the first linear deformation structure 301 and the bending deformation structure 302 in the contracted state, and the width of another partition 304 is greater than the length of the second linear deformation structure 303 in the contracted state.

[0040] In the present invention, by providing a wider partition 304, the partition 304 can form a hollow groove at the top of the subframe when casting the subframe, so that the variable core 3 can be taken out from the subframe in the contracted state.

[0041] It is worth noting that, as Figures 5 to 11As shown in the figure, the first linear deformation structure 301 involved in the present invention includes a first end block 3011, a first elastic cord 3012, a first support frame 3013, and a connection frame 3014; the four first elastic cords 3012 are installed at the four corners of the first end block 3011, and the other ends of the four first elastic cords 3012 are installed at the four corners of the connection frame 3014. The four first elastic cords 3012 are connected through the four corners of eight first support frames 3013. The eight first support frames 3013 are arranged equidistantly inside the elastic sleeve 305, and the outer side of the first support frame 3013 is attached to the inner wall of the elastic sleeve 305.

[0042] The bending deformation structure 302 includes a support beam 3021, a connecting rod 3022, and a connecting cable 3023; the connecting rod 3022 is a shape memory metal. When the nine support beams 3021 and the eight connecting rods 3022 extend, a bent extension structure is formed. And the adjacent two sets of bent extension structures are connected by the connecting cable 3023 to form a bending deformation framework. The two bending deformation frameworks are respectively installed at the top and bottom of one side of the connection frame 3014. A connecting rod 3022 is slidably connected between two adjacent support beams 3021, and the eight connecting rods 3022 are arranged in a stepped manner on the nine support beams 3021.

[0043] The second linear deformation structure 303 includes a second end block 3031, a second elastic cord 3032, and a second support frame 3033; the four second elastic cords 3032 are connected to the four corners of the two second end blocks 3031, and the four second elastic cords 3032 are connected through the four corners of six second support frames 3033. The six second support frames 3033 are arranged equidistantly inside the elastic sleeve 305, and the outer side of the second support frame 3033 is attached to the inner wall of the elastic sleeve 305.

[0044] In the present invention, the first linear deformation structure 301 relies on the first elastic cord 3012 to pass through the first support frame 3013 and cooperate with the air pump to inflate, so that the first end block 3011 moves, driving the elastic cord to be tightened or relaxed, realizing extension and contraction. The equidistantly arranged first support frames 3013 are attached to the inner wall of the elastic sleeve 305 to ensure stable deformation. In the bending deformation structure 302, the connecting rod 3022 of the shape memory metal slides between the support beams 3021. When inflated, the elastic sleeve 305 drives the support beam 3021 to move. When the support beam 3021 moves, the connecting rod 3022 moves accordingly. The connecting rods 3022 arranged in a stepped manner form a bent extension structure, and the connecting cable 3023 connects them into a framework to shape the bent part of the subframe. The second linear deformation structure 303 is similar to the first linear deformation structure 301 in principle. The second elastic cord 3032 passes through the second support frame 3033 and realizes expansion and contraction inside the elastic sleeve 305, thereby realizing the extension and contraction of the core.

[0045] Furthermore, as Figures 8 to 11 shown, at the four corners of the second end block 3031 involved in the present invention, second adsorption blocks 3034 are installed. The second adsorption blocks 3034 are adsorbed and connected to first adsorption blocks 3024, and the four first adsorption blocks 3024 are respectively connected to the four corners of the bending deformation skeleton outer elastic sleeve 305.

[0046] By providing the first adsorption blocks 3024 and the second adsorption blocks 3034 on the second end block 3031 and the elastic sleeve 305 outside the bending deformation skeleton, the first adsorption blocks 3024 and the second adsorption blocks 3034 can connect the bending deformation structure 302 and the second linear deformation structure 303 together, thereby producing a hollow subframe with internal communication.

[0047] Still further, as Figures 6 to 11 shown, the air inlet 4 involved in the present invention is also communicated with a cooling structure 306 and an external air conditioner. And the three cooling structures 306 are respectively arranged in the two first linear deformation structures 301 and the second linear deformation structure 303. The cooling structure 306 includes an air inlet pipe 3061 and a connecting hose 3062; several air inlet pipes 3061 are respectively connected to a first support frame 3013 or a second support frame 3033, and the several air inlet pipes 3061 are connected through the connecting hose 3062. The end air inlet pipe 3061 is communicated with the variable core 3, and the air inlet pipe 3061 is made of heat-conducting metal.

[0048] The variable core 3 is connected to an air outlet 5, and the air outlet 5 is communicated with an external air extraction pump, and electric control valves are arranged on both the air inlet pump and the air extraction pump.

[0049] Through the cooling structure 306 of the present invention, during demolding, the air conditioner flows low-temperature gas along the air inlet 4, and the gas flows through each support frame by means of the air inlet pipe 3061 and the connecting hose 3062. The core is cooled in all directions through the support frame. The air outlet 5 is communicated with the air outlet pipe of the upper mold 1, and the gas is discharged by opening the electric control valve. After the casting is cooled to the demolding temperature, it is convenient for the casting to be separated from the core more easily. The present invention can reduce the demolding resistance through the cooling structure 306, avoid demolding damage, and improve the qualified product rate.

[0050] Even further, as Figure 5 and Figure 14As shown in the figure, on both sides of the elastic sleeve 305 involved in the present invention, five vertical forming parts 3051 are equidistantly arranged along the long axis direction. The forming part 3051 is of an S-shaped structure, and an inner groove is provided inside the forming part 3051. At the top and bottom of the elastic sleeve 305, fifty horizontal shrinkage grooves 3052 are equidistantly arranged along the long axis direction. The shrinkage groove 3052 is of a V-shaped structure, and the larger opening end of the V-shaped structure faces the inside of the elastic sleeve 305.

[0051] By providing the forming part 3051 with an S-shaped structure, when the elastic sleeve 305 is filled with gas, the forming part 3051 can be pushed outwards by the gas through the inner groove, so as to form an S-shaped strengthening groove inside the subframe during casting, and the structural strength of the subframe is enhanced through the strengthening groove. Through the S-shaped forming part 3051 of the present invention, a strengthening groove structure can be formed on the inner wall of the subframe during casting, thereby increasing the structural strength of the subframe.

[0052] By providing the shrinkage groove 3052 with a V-shaped structure, when the elastic sleeve 305 shrinks, the V-shaped shrinkage groove 3052 becomes the starting point of deformation and bends first, enabling the elastic sleeve 305 to easily shrink and deform and quickly fold together. By providing the V-shaped shrinkage groove 3052, the shrinkage process of the elastic sleeve 305 is accelerated, and the time required for deformation and demoulding is shortened.

[0053] As Figures 1 to 14 shown, a casting method for a low-pressure casting mold of a large aluminum alloy subframe involved in the present invention includes the following steps: S1. Mold preparation and installation: Install the upper mold 1 and the lower mold 2 on the casting equipment, check the connection stability of each component, connect to the external air inlet pump through the air inlet 4, ensure its normal communication with the first linear deformation structure 301 and the second linear deformation structure 303, and at the same time connect the cooling structure 306 to the external air conditioner, and connect the air outlet 5 to the external air extraction pump, and debug the electric control valve to ensure smooth air passage and precise control; S2. Variable core stretching: Start the air inlet pump and supply gas to the air inlet 4. After the gas flows in, the first end block 3011 moves, driving the first elastic cable 3012 of the first linear deformation structure 301 to be tightened, so that the first support frame 3013 is stretched equidistantly and cooperates with the gas to support the elastic sleeve 305; In the bending deformation structure 302, the elastic sleeve 305 drives the support beam 3021 to move, and the connecting rod 3022 slides between the support beams 3021 and is distributed in a stepped shape to form a bent extension structure, and the connecting cable 3023 connects it into a framework; The second linear deformation structure 303 is stretched synchronously, and the second adsorption block 3034 is adsorbed and connected to the first adsorption block 3024 to ensure the stable connection of the bending deformation structure 302 and the second linear deformation structure 303, and each structure closely cooperates to construct a complete core framework; S3. Pour aluminum alloy: Slowly pour the aluminum alloy liquid melted to an appropriate temperature into the mold cavity 6 formed by the upper mold 1 and the lower mold 2. The aluminum alloy liquid surrounds the molding structure composed of the variable core 3 and the elastic sleeve 305. As the aluminum alloy liquid is filled, it gradually takes shape in the mold cavity. During this process, the molding part 3051 of the S-shaped structure is ejected by gas. After the aluminum alloy liquid solidifies, an S-shaped strengthening groove is formed inside the subframe to enhance the structural strength. S4. Cooling before demolding: After the pouring of the aluminum alloy liquid is completed, start the external air conditioner. The low-temperature gas passes through the intake pipe 3061 of the cooling structure 306 and is shunted to each intake pipe 3061 made of heat-conducting metal through the connecting hose 3062. It passes through the first support frame 3013 and the second support frame 3033 to cool the variable core 3 in all directions, accelerating the solidification of the casting. S5. Demolding operation: When the casting is cooled to near the demolding temperature, open the electromagnetic valve at the air outlet 5, and extract the gas inside the core through the air extraction pump to reduce the internal air pressure. The first linear deformation structure 301, the bending deformation structure 302, and the second linear deformation structure 303 start to contract under the action of the internal pressure change and their own structural characteristics. The V-shaped contraction groove 3052 bends first, the elastic sleeve 305 quickly contracts and deforms and folds, and the overall length of the variable core 3 shortens. It smoothly separates from the casting through the casting hole reserved by the partition 304, and then through the external jacking equipment, the demolding process is completed by jacking, and finally a high-quality aluminum alloy subframe with hollow front and rear beams and internal strengthening grooves is obtained.

[0054] The embodiments disclosed in the present invention are preferred embodiments, but are not limited thereto. Those of ordinary skill in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not depart from the spirit of the present invention, they are within the protection scope of the present invention.

Claims

1. A large aluminum alloy subframe low-pressure casting mold, characterized in that: It comprises an upper mold and a lower mold, wherein the bottom end of the upper mold is connected to two variable cores; The variable core has an extended state and a contracted state, and includes two first straight deformation structures, two curved deformation structures, and a second straight deformation structure; In the extended state, the first linear deformation structure and the curved deformation structure connected thereto are extended and elongated, and the second linear deformation structure is extended and elongated, and both ends are respectively attached to one end of the two curved deformation structures, and are used as the skeleton of the core in the upper mold and the lower mold to assist the sub-frame in casting the hollow front and rear beams; in the contracted state, the first linear deformation structure and the curved deformation structure connected thereto are contracted and shortened, and the second linear deformation structure is contracted and shortened, and is used for demoulding after casting the hollow front and rear beams of the sub-frame; The two first linear deformation structures and the second linear deformation structure are respectively connected to three air inlets, and the air inlets are connected to an external air intake pump. Partitions are installed at the air inlets. The first linear deformation structure and the curved deformation structure are covered with elastic sleeves, and the second linear deformation structure is covered with another elastic sleeve.

2. A large aluminum alloy subframe low pressure casting mold according to claim 1, characterized in that: The widths of the two partitions are greater than the lengths of the first linear deformation structure and the curved deformation structure in the contracted state, and the width of the other partition is greater than the length of the second linear deformation structure in the contracted state.

3. A large aluminum alloy subframe low pressure casting mold according to claim 2, characterized in that: The upper die and the lower die are provided with a die cavity, and the die cavity and the extended state variable core with an elastic sleeve form a sub-frame molding structure for casting the sub-frame.

4. A large aluminum alloy subframe low pressure casting mold according to claim 3, characterized in that: The first linear deformation structure includes a first end block, a first elastic cable, a first support frame, and a connecting frame; The four first elastic cables are installed at the four corners of the first end block, and the other ends of the four first elastic cables are installed at the four corners of the connecting frame. The four first elastic cables are connected through the four corners of a number of first support frames, and the several first support frames are arranged equidistantly inside the elastic sleeve, and the outer sides of the first support frames are attached to the inner wall of the elastic sleeve.

5. A large aluminum alloy subframe low pressure casting mold according to claim 4, characterized in that: The bending deformation structure includes a support beam, a connecting rod, and a connecting cable; The connecting rod is a deformation memory metal. When the support beams and the connecting rods are extended, a curved extension structure is formed. Two adjacent groups of curved extension structures are connected by connecting cables to form a curved deformation skeleton. The two curved deformation skeletons are respectively installed on the top and bottom ends of one side of the connecting frame. A connecting rod is slidably connected between two adjacent support beams, and the connecting rods are distributed in a stepped manner on the support beams.

6. A large aluminum alloy subframe low pressure casting mold according to claim 5, characterized in that: The second linear deformation structure includes a second end block, a second elastic cable, and a second support frame; The four second elastic ropes are connected at the four corners of the two second end blocks, and the four second elastic ropes are connected at the four corners of a plurality of second support frames, and the plurality of second support frames are arranged equidistantly inside the elastic sleeve, and the outer sides of the second support frames are fitted on the inner wall of the elastic sleeve.

7. A large aluminum alloy subframe low pressure casting mold according to claim 6, characterized in that: Second adsorption blocks are installed at the four corners of the second end block, the second adsorption blocks are adsorbed and connected to the first adsorption blocks, and the four first adsorption blocks are respectively connected to the four corners of the elastic sleeve outside the bending deformation skeleton.

8. A large aluminum alloy subframe low pressure casting mold according to claim 7, characterized in that: The air inlet is also connected to a cooling structure and an external air conditioner, and three cooling structures are respectively arranged in the two first linear deformation structures and the second linear deformation structure, and the cooling structure includes an air inlet pipe and a connecting hose; The plurality of air intake pipes are respectively connected to the first support frame or the second support frame, and the plurality of air intake pipes are connected by a connecting hose, and the air intake pipes at the ends are connected to the variable core.

9. A large aluminum alloy subframe low pressure casting mold according to claim 8, characterized in that: The variable core is connected with an air outlet, and the air outlet is connected to an external air pump, and both the air inlet pump and the air pump are provided with an electric control valve.

10. A large aluminum alloy subframe low pressure casting mold according to claim 9, characterized in that: A plurality of vertical forming parts are equidistantly arranged on both sides of the elastic sleeve along the long axis direction, the forming parts are of S-shaped structure, and an inner groove is arranged on the inner side of the forming parts; a plurality of horizontal shrinkage grooves are equidistantly arranged on the top and bottom ends of the elastic sleeve along the long axis direction, the shrinkage grooves are of V-shaped structure, and the larger opening end of the V-shaped structure faces the inner side of the elastic sleeve.

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