An aluminum alloy low-pressure casting device and its process

Abstract

This application relates to the technical field of low-pressure casting, and specifically discloses an aluminum alloy low-pressure casting device and its process. The aluminum alloy low-pressure casting device includes a hydraulic system, a forming module, a holding furnace, a pressurizing system, and a control system. The forming module includes a lower module. The bottom of the lower module is provided with a liquid inlet. The inner wall of the upper half of the liquid inlet is in an inverted cone shape, and the inner wall of the lower half is in a cone shape. A separating constriction is formed between the upper half and the lower half. A cooling component is provided on the lower module corresponding to the upper half of the liquid inlet, and a heating component is provided corresponding to the lower half of the liquid inlet. By setting the inverted cone structure and the positive cone structure, the overall liquid inlet is in a counter cone shape, so that the molten aluminum that needs to be cooled and the molten aluminum that needs to be heated can be distinguished, so as to minimize the contact area between the two parts of the molten aluminum, thereby maximizing the avoidance of the mutual influence between the cooling part and the heating part and ensuring the separation effect.

Description

Technical Field

[0001] This application relates to the technical field of low-pressure casting, and particularly relates to an aluminum alloy low-pressure casting device and its process. Background Art

[0002] The low-pressure casting machine is a general device for aluminum alloy low-pressure casting and can be widely used in the production of aluminum alloy castings in the automotive, motorcycle, instrument, textile machinery, and aerospace industries. The low-pressure casting machine consists of a main machine, a hydraulic system, a molten pool type holding furnace, a liquid level pressurizing device, an electrical control system, a mold cooling system, and other parts.

[0003] During the casting process, the molten metal (such as molten aluminum) is introduced into a sealed crucible (or sealed tank), and then dry compressed air is introduced. Under the action of the gas pressure, the molten metal rises along the riser pipe, enters the cavity smoothly through the gate, and maintains the gas pressure on the liquid surface in the crucible until the casting is completely solidified. Then, the gas pressure on the liquid surface is released, so that the unfrozen molten metal in the riser pipe flows back into the crucible, and then the mold is opened to form the casting. In actual production, it is found that there are some problems, that is, when the casting in the cavity is cooled and formed, the molten metal at the liquid outlet in the lower mold solidifies due to cooling, and the molten metal in the riser pipe should flow back into the holding furnace (crucible) when the casting is completely formed. Therefore, there will be solid-phase and liquid-phase molten metal at the position near the top of the riser pipe. If the temperature is too high, the cooling and forming of the casting will slow down; if the temperature is too low, more molten metal in the riser pipe will solidify, affecting demolding. Therefore, it is very necessary to provide a low-pressure casting machine that can balance the reflux effect and the demolding effect. Summary of the Invention

[0004] The purpose of this application is to provide an aluminum alloy low-pressure casting device and its process to solve the above problems.

[0005] To achieve the above purpose, the technical solution of this application is as follows:

[0006] In a first aspect, this application provides an aluminum alloy low-pressure casting device, including a hydraulic system, a forming module, a holding furnace, a pressurizing system, and a control system. The forming module includes a lower module. The bottom of the lower module is provided with a liquid inlet. The inner wall of the upper half of the liquid inlet is in an inverted cone shape, and the inner wall of the lower half is in a cone shape. A partition constriction is formed between the upper half and the lower half. A cooling component is provided on the lower module corresponding to the upper half of the liquid inlet, and a heating component is provided corresponding to the lower half of the liquid inlet.

[0007] Preferably, the lower module includes a bottom plate. A liquid inlet pipe is provided on the bottom plate, and the liquid inlet is arranged in the liquid inlet pipe. A partition groove is provided on the outer peripheral wall of the liquid inlet pipe corresponding to the partition constriction, and the partition groove is configured to prevent heat exchange between the upper half and the lower half of the liquid inlet.

[0008] Preferably, a vibration part is provided in the partition groove.

[0009] Preferably, the lower die set further includes a first template and a second template, which are slidably arranged opposite to each other on the bottom plate; sliding grooves extending into the interior of the bottom plate are respectively provided on the side edges of the bottom plate corresponding to the first template and the second template, a wedge plate is provided in the sliding groove, an abutting inclined surface is provided on the wedge plate, and the abutting inclined surface gradually slopes downward along the direction pointing to the notch of the sliding groove; a ejector rod is slidably arranged in the bottom plate corresponding to the wedge plate, and the bottom end of the ejector rod abuts against the abutting inclined surface; the wedge plate on one side of the first template is connected to the first template, and the wedge plate on one side of the second template is connected to the second template.

[0010] Preferably, the abutting inclined surface includes a first inclined surface and a second inclined surface, the first inclined surface is closer to the notch of the sliding groove than the second inclined surface, and the inclination degree of the first inclined surface is less than that of the second inclined surface.

[0011] Preferably, the forming die set further includes an upper die set, an annular cavity is provided inside the upper die set, two sets of expansion blocks are slidably arranged radially on the outer peripheral wall of the upper die set, the two sets of expansion blocks are symmetrically arranged, a contact rod is provided in one side of the expansion block located in the annular cavity, a variable-diameter rotating column is arranged between the two contact rods, one end of the variable-diameter rotating column is connected with a spring, and the other end of the spring is connected with the transmission shaft of the motor.

[0012] Preferably, an air inlet is provided in the lower half of the liquid inlet.

[0013] Preferably, an annular groove is provided on the inner wall of the lower half of the liquid inlet corresponding to the air inlet, the annular groove includes a vertically annular arc surface and a horizontally annular plane, the annular arc surface faces the axis of the liquid inlet pipe, and the annular plane is arranged downward.

[0014] Preferably, a flow channel groove is provided on the inner wall of the upper half of the liquid inlet, the number of the flow channel grooves is multiple, and the multiple flow channel grooves are arranged at intervals in the circumferential direction; the end of the flow channel groove far away from the partition beam opening is located in the inner wall of the upper half of the liquid inlet.

[0015] In a second aspect, an aluminum alloy low-pressure casting process using the above aluminum alloy low-pressure casting device is also provided, including: S1. Preheat the forming module and then spray a mold release agent; S2. Close the mold of the forming module through the hydraulic system, and after closing the mold, introduce compressed gas at 50 kPa into the interior of the forming module for pressure holding. If the pressure does not drop by more than 2 kPa after 5 minutes of pressure holding, it is considered qualified; S3. Melt the aluminum liquid, skim off the floating slag and detect the hydrogen content; the hydrogen content is required to be ≤ 0.15 mL / 100 g; S4. Pour the aluminum liquid processed in S3 into the holding furnace and slowly pressurize it through the pressurizing system; S5. After pressure filling and forming, set the shape for 3 to 10 minutes and perform auxiliary cooling; S6. Release the pressure step by step in a gradient; S7. Open the mold and take out the formed casting to complete the casting.

[0016] In the aluminum alloy low-pressure casting device disclosed in this application, by setting an inverted cone structure and a positive cone structure, the overall liquid inlet is a conical structure, so as to distinguish the aluminum liquid that needs to be cooled from the aluminum liquid that needs to be heated, and to minimize the contact area between the two parts of the aluminum liquid, thereby maximizing the avoidance of the mutual influence between the cooling part and the heating part and ensuring the separation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of this application;

[0018] Figure 2 It is a three-dimensional view of the lower mold structure of this application;

[0019] Figure 3 It is a sectional view of the lower mold structure of this application;

[0020] Figure 4 It is Figure 3 a partial enlarged view of part A in

[0021] Figure 5 It is a top view of the lower mold structure of this application;

[0022] Figure 6 It is Figure 5 a sectional view of the A-A section in

[0023] Figure 7 It is Figure 5 a sectional view of the B-B section in

[0024] Figure 8 It is a schematic diagram of the structure at the holding furnace of this application;

[0025] Figure 9 It is a schematic diagram of the structure at the upper mold assembly of this application;

[0026] Figure 10 It is Figure 9 a partial enlarged view of part B in

[0027] Figure 11 This is another perspective schematic diagram of the upper mold unit in the present application.

[0028] In the figure:

[0029] 1. Hydraulic system; 2. Molding mold unit; 201. First template; 202. Second template; 203. Bottom plate; 205. Partition groove; 206. Air inlet; 207. Cooling component; 208. Partition constriction; 209. Liquid inlet pipe; 210. Upper half; 21. Lower mold unit; 211. Runner groove; 212. Lower half; 213. Annular groove; 214. Annular plane; 215. Annular arc surface; 22. Upper mold unit; 220. Annular cavity; 3. Insulation furnace; 4. Sliding groove; 40. Wedge plate; 41. First inclined surface; 42. Second inclined surface; 43. Ejector rod; 5. Lift pipe; 50. Resistance heating tape; 6. Expansion block; 60. Contact rod; 61. Variable-diameter rotating column; 610. Arc side surface; 611. Contact plane; 62. Spring. Detailed implementation mode

[0030] Now, the present application will be further described in detail with reference to the accompanying drawings. The accompanying drawings are simplified schematic diagrams, which only illustrate the basic structure of the present application in a schematic manner, so they only show the components related to the present application.

[0031] As Figures 1 to 4 shown, in the first aspect, the present application provides an aluminum alloy low-pressure casting device, including a hydraulic system 1, a molding mold unit 2, an insulation furnace 3, a pressurization system and a control system. The molding mold unit 2 includes a lower mold unit 21. The bottom of the lower mold unit 21 is provided with a liquid inlet. The inner wall of the upper half 210 of the liquid inlet is in an inverted cone shape, and the inner wall of the lower half 212 is in a cone shape. A partition constriction 208 is formed between the upper half 210 and the lower half 212; a cooling component 207 is provided on the lower mold unit 21 corresponding to the upper half 210 of the liquid inlet, and a heating component is provided corresponding to the lower half 212 of the liquid inlet.

[0032] The hydraulic system 1 is used to realize the mold opening and mold closing of the molding mold unit 2. The insulation furnace 3 is used to keep the molten aluminum warm. The pressurization system is used to pressurize the insulation furnace 3 so that the molten aluminum in the insulation furnace 3 rises along the lift pipe 5. The control system is used to control the reasonable movement of each execution system or component in the entire low-pressure casting device. It should be noted that the hydraulic system 1, the insulation furnace 3, the pressurization system and the control system have been widely used in the field of low-pressure casting and are prior arts. Their structures and working principles will not be described in detail in this embodiment.

[0033] The forming module 2 includes a lower module 21. A liquid inlet is provided on the lower module 21 and is used to dock with the lifting pipe 5. The inner wall of the liquid inlet is divided into two parts. The upper half 210 is of an inverted cone structure, and the lower half 212 is of a cone structure. The two parts are completely connected, and a constriction is formed at the connection position of the two parts, that is, a separating constriction 208, so as to facilitate the solidification of the molten aluminum in the upper half 210 and the reflux of the molten aluminum in the lower half 212 in the subsequent process.

[0034] The upper half 210 and the lower half 212 are only distinguished in terms of orientation and do not mean that the upper half 210 and the lower half 212 divide the entire liquid inlet equally.

[0035] The cooling component 207 is correspondingly arranged outside the upper half 210 for accelerating cooling, and the heating component is correspondingly arranged outside the lower half 212 for maintaining the temperature of the molten aluminum and assisting in reflux.

[0036] A resistance heating tape 50 is provided outside the lifting pipe 5.

[0037] The cooling component 207 can be a circulating water cooling pipe, and the heating component can also be a resistance heating tape 50.

[0038] By setting the inverted cone structure and the positive cone structure, the overall liquid inlet is of an opposing cone structure, so as to distinguish the molten aluminum that needs to be cooled from the molten aluminum that needs to be heated, and to minimize the contact area between the two parts of the molten aluminum, thereby avoiding the mutual influence between the cooling part and the heating part to the greatest extent and ensuring the separation effect.

[0039] In some further embodiments, the lower module 21 includes a bottom plate 203. A liquid inlet pipe 209 is provided on the bottom plate 203, and the liquid inlet is arranged in the liquid inlet pipe 209. A separating groove 205 is provided on the outer peripheral wall of the liquid inlet pipe 209 corresponding to the separating constriction 208, and the separating groove 205 is set to prevent heat exchange between the upper half 210 and the lower half 212 of the liquid inlet.

[0040] The lower module 21 includes a bottom plate 203. The bottom plate 203 is part of the enclosure forming the cavity. A liquid inlet pipe 209 is arranged at its lower part, and the liquid inlet is located in the liquid inlet pipe 209. In order to avoid the heat conduction effect, a separating groove 205 is opened on the outer peripheral wall of the liquid inlet pipe 209. The separating groove 205 is an annular groove 213, and its cross-section can be triangular or rectangular. Moreover, the separating groove 205 corresponds to the separating constriction 208 in the liquid inlet in the horizontal direction. Under the action of the separating groove 205 and the separating constriction 208, the cooled part and the heated part in the liquid inlet pipe 209 can be well separated, so that the degree of mutual influence during heating and cooling of each part will be reduced. Thus, both the cooling time of the bottom part of the casting can be reduced and the reflux amount of the molten aluminum can be increased, taking into account both efficiency and cost.

[0041] In some further embodiments, a vibration part is provided in the separating groove 205.

[0042] A vibration part is provided in the separation groove 205. The vibration part can be a piezoelectric ceramic actuator, which is used to apply a certain vibration to the liquid inlet pipe 209. One is to increase the reflux of the molten aluminum and avoid adhesion to the inner wall of the riser pipe 5. The other is to facilitate the demolding of the casting after molding and avoid damage to the outer wall of the casting during demolding by mechanical force.

[0043] The piezoelectric ceramic actuator can be installed by bonding or by clamping with a clamp.

[0044] It should be noted that the piezoelectric ceramic actuator is widely used in the industrial field and is an existing technology. Its structure and working principle will not be elaborated in this embodiment.

[0045] In other embodiments, the vibration part can also be a vibration motor.

[0046] As Figures 5 to 8 shown, in some further embodiments, the lower mold set 21 further includes a first template 201 and a second template 202. The first template 201 and the second template 202 are slidably arranged opposite to each other on the bottom plate 203. On the bottom plate 203, sliding grooves 4 extend inwardly from the side edges corresponding to the first template 201 and the second template 202 respectively. A wedge plate 40 is provided in the sliding groove 4. The wedge plate 40 is provided with an abutting inclined surface, and the abutting inclined surface gradually slopes downward along the direction pointing to the notch of the sliding groove 4. A ejector rod 43 is slidably provided in the bottom plate 203 corresponding to the wedge plate 40, and the bottom end of the ejector rod 43 abuts against the abutting inclined surface. The wedge plate 40 on one side of the first template 201 is connected to the first template 201, and the wedge plate 40 on one side of the second template 202 is connected to the second template 202.

[0047] The first template 201 and the second template 202 can slide relatively close to or relatively away from each other on the bottom plate 203 to realize mold closing and mold opening.

[0048] Define the mold opening direction of the first template 201 as the first direction, and the mold opening direction of the second mold as the second direction. The first direction and the second direction are opposite and relative to each other.

[0049] Sliding grooves 4 are provided on both sides of the side wall in the bottom plate 203 on one side of the first direction and on one side of the second direction. The sliding grooves 4 extend correspondingly inwardly but do not penetrate the bottom plate 203. The sliding grooves 4 on the side of the liquid inlet on the two side walls are arranged in a staggered manner in sequence, that is, in the horizontal direction, along the direction perpendicular to the first direction, they can be in sequence: the sliding groove 4 with an opening facing the first direction, the sliding groove 4 with an opening facing the second direction, and the sliding groove 4 with an opening facing the first direction.

[0050] The bottom plate 203 is provided with sliding holes, and a ejector rod 43 is slidably arranged in the sliding holes. The sliding holes are all located directly above the sliding groove 4 and communicate with the sliding groove 4. The ejector rod 43 is slidably arranged in the sliding holes. A wedge plate 40 is slidably arranged in the sliding groove 4. The top of the wedge plate 40 has an inclined surface structure, that is, an abutting inclined surface. Among them, the abutting inclined surface in the sliding groove 4 with the opening facing the first direction gradually slopes downward along the first direction, and the abutting inclined surface in the sliding groove 4 with the opening facing the second direction gradually slopes downward along the second direction, so as to ensure that when the wedge plate 40 slides out of the sliding groove 4, it can continuously abut against the ejector rod 43, so that the ejector rod 43 abuts against the formed casting to realize demolding.

[0051] In addition, the wedge plates 40 in the sliding grooves 4 with the openings facing the first direction are all connected to the first template 201. That is, when the first template 201 is opened along the first direction, it will synchronously drive the wedge plates 40 to move, so as to synchronously realize the upward pushing of the casting during the mold opening process.

[0052] In traditional low-pressure casting machines, the ejection mechanism is usually set separately, and an additional independent driving structure needs to be set, and it often needs to occupy a part of the position below the forming module 2. In this embodiment, the setting of the ejection mechanism is omitted, and the two actions of ejection and mold opening are linked together to realize the synchronous triggering of the two, which not only avoids the cumbersome PLC execution timing, but also ensures the stability of the action execution, and at the same time makes the structure of the whole device more concise.

[0053] Please refer to Figure 6 and Figure 7 , in some further embodiments, the abutting inclined surface includes a first inclined surface 41 and a second inclined surface 42. The first inclined surface 41 is closer to the notch of the sliding groove 4 than the second inclined surface 42, and the inclination degree of the first inclined surface 41 is less than that of the second inclined surface 42.

[0054] In order to ensure the stability of the abutting process, the abutting of the wedge plate 40 against the ejector rod 43 is carried out in stages. Specifically, the abutting inclined surface includes a first inclined surface 41 and a second inclined surface 42. The first inclined surface 41 is closer to the notch of the sliding groove 4, and the inclination degree of the first inclined surface 41 is less than that of the second inclined surface 42, so as to ensure that when the wedge plate 40 slides out of the sliding groove 4, first the first inclined surface 41 abuts against the ejector rod 43, and then the second inclined surface 42 abuts against the ejector rod 43, so as to slowly release the initial adhesion force between the casting and the mold, avoid local stress concentration, and then increase the speed to reduce the demolding time.

[0055] Such as Figures 9 to 11As shown, in some further embodiments, the molding module 2 further includes an upper module 22. An annular cavity 220 is provided inside the upper module 22. Two sets of expansion blocks 6 are slidably arranged radially on the outer peripheral wall of the upper module 22. The two sets of expansion blocks 6 are symmetrically arranged. An abutting rod 60 is provided on one side of the expansion block 6 located in the annular cavity 220. A variable-diameter rotating column 61 is provided between the two abutting rods 60. One end of the variable-diameter rotating column 61 is connected to a spring 62, and the other end of the spring 62 is connected to the transmission shaft of the motor.

[0056] When the upper module 22 rises under the action of the hydraulic system 1, it will synchronously drive and gradually rise, and then fall into the mold-taking mechanism through vibration or manual knocking.

[0057] In this embodiment, in order to prevent the casting from accidentally falling before the mold-taking mechanism arrives, two sets of expansion blocks 6 are symmetrically arranged in the upper module 22. The two sets of expansion blocks 6 are both slidably arranged along the central direction of the upper module 22. An abutting rod 60 is provided on the side of the two sets of expansion blocks 6 facing each other. The ends of the two abutting rods 60 facing away from the expansion blocks 6 face each other but do not abut. A variable-diameter rotating column 61 is provided in the area separated by the ends of the two abutting rods 60. In the initial state, the expansion blocks 6 do not slide and maintain balance under the abutting action of the abutting rods 60 and the variable-diameter rotating column 61. When the variable-diameter rotating column 61 rotates, the distance between the two abutting rods 60 becomes larger, respectively causing the two sets of expansion blocks 6 to move away from each other, that is, the outer wall of the upper module 22 will have a slight bulge, so as to achieve a certain clamping of the casting to prevent the casting from falling.

[0058] However, the backward sliding of the two expansion blocks 6 may cause damage to the casting. To solve this problem, a spring 62 is specially provided to make the expansion blocks 6 expand adaptively or flexibly, that is, the motor drives the spring 62 to rotate. The rotating spring 62 will generate a rotating force on the variable-diameter rotating column 61 but not a mechanical rigid rotation, so that the expansion blocks 6 will more generate an adaptive acting force of expanding and abutting on the casting, thus avoiding causing certain damage to the casting.

[0059] The variable-diameter rotating column 61 includes two arc-shaped sides 610 and two abutting planes 611. The two abutting planes 611 are used to ensure the stability of the two sets of expansion blocks 6 in the initial state, and the two arc-shaped sides 610 are used to facilitate the rotation of the variable-diameter rotating column 61.

[0060] Please refer to Figure 4 As shown, in some further embodiments, an air inlet 206 is provided in the lower half 212 of the liquid inlet.

[0061] When demolding after the casting is formed, gas can be introduced into the air inlet 206, thereby increasing the reflux of the molten aluminum. At the same time, the airflow will also form a certain separation effect between the aluminum solid cooled and formed in the upper half 210 and the inner wall, so as to facilitate the demolding of the two and avoid damage to the casting under the action of mechanical force.

[0062] To prevent the molten aluminum from seeping out of the pores, a porous ceramic filter plate (porous ceramic with slide rails) and a metal support mesh can be provided in the air inlet.

[0063] In some further embodiments, an annular groove 213 is provided on the inner wall of the lower half 212 of the liquid inlet corresponding to the air inlet 206. The annular groove 213 includes a vertically annular arc surface 215 and a horizontally annular plane 214. The annular arc surface 215 faces the axis of the liquid inlet pipe 209, and the annular plane 214 is arranged downward.

[0064] The airflow blown into the lower half 212 will move toward the middle and lower parts under the action of the annular plane 214 and the annular arc surface 215 to prevent the molten aluminum from adhering to the inner wall.

[0065] The annular plane 214 and the annular arc surface 215 are mainly used to change the direction of the airflow when it enters the liquid inlet.

[0066] In some further embodiments, a flow channel groove 211 is provided on the inner wall of the upper half 210 of the liquid inlet. The number of the flow channel grooves 211 is multiple, and the multiple flow channel grooves 211 are arranged at intervals in the circumferential direction; one end of the flow channel groove 211 far from the separation nozzle 208 is located in the inner wall of the upper half 210 of the liquid inlet.

[0067] The flow channel groove 211 can, to a certain extent, increase the airflow entering between the inner wall of the upper half 210 and the solidified aluminum solid, so as to increase the upward pushing force on the casting.

[0068] In a second aspect, an aluminum alloy low-pressure casting process using the above aluminum alloy low-pressure casting device is also provided, including: S1. Preheat the forming module 2 and then spray a demolding agent; S2. Close the forming module 2 through the hydraulic system 1, and after closing the mold, introduce compressed gas of 50 kPa into the inside of the forming module 2 for pressure holding. If the pressure does not drop by more than 2 kPa after 5 minutes of pressure holding, it is considered qualified; S3. Melt the molten aluminum, skim off the floating slag and detect the hydrogen content; it is required that the hydrogen content ≤ 0.15 mL / 100 g; S4. Pour the molten aluminum processed in S3 into the holding furnace 3 and slowly pressurize through the pressurizing system; S5. After pressure charging and forming, keep it for 3 to 10 minutes for shaping and perform auxiliary cooling; S6. Release the pressure step by step according to a gradient; S7. Open the mold and take out the formed casting to complete the casting.

[0069] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of this application's creation.

Claims

1. A low-pressure casting device for aluminum alloy, comprising a hydraulic system (1), a forming module (2), a holding furnace (3), a pressurizing system and a control system, characterized in that, The forming module (2) includes a lower module (21). A liquid inlet is provided at the bottom of the lower module (21). The inner wall of the upper half (210) of the liquid inlet is in an inverted conical shape, and the inner wall of the lower half (212) is in a conical shape. A separating constriction (208) is formed between the upper half (210) and the lower half (212); a cooling component (207) is provided on the lower module (21) corresponding to the upper half (210) of the liquid inlet, and a heating component is provided corresponding to the lower half (212) of the liquid inlet; the forming module (2) further includes an upper module (22). An annular cavity (220) is provided inside the upper module (22). Two sets of expansion blocks (6) are slidably provided radially on the outer peripheral wall of the upper module (22). The two sets of expansion blocks (6) are symmetrically arranged. An abutting rod (60) is provided on one side of the expansion block (6) located in the annular cavity (220). A variable-diameter rotating column (61) is provided between the two abutting rods (60). One end of the variable-diameter rotating column (61) is connected to a spring (62), and the other end of the spring (62) is connected to the transmission shaft of the motor.

2. The aluminum alloy low-pressure casting device according to claim 1, characterized in that, The lower module (21) includes a bottom plate (203). A liquid inlet pipe (209) is provided on the bottom plate (203). The liquid inlet is arranged in the liquid inlet pipe (209); a separating groove (205) is provided on the outer peripheral wall of the liquid inlet pipe (209) corresponding to the separating constriction (208). The separating groove (205) is configured to prevent heat exchange between the upper half (210) and the lower half (212) of the liquid inlet.

3. The aluminum alloy low-pressure casting device according to claim 2, characterized in that, A vibration part is provided in the separating groove (205).

4. The aluminum alloy low-pressure casting device according to claim 2, characterized in that, The lower module (21) further includes a first template (201) and a second template (202). The first template (201) and the second template (202) are slidably arranged opposite to each other on the bottom plate (203); sliding grooves (4) are respectively provided on the bottom plate (203) corresponding to the side edges of the first template (201) and the second template (202) and extending into the interior of the bottom plate (203). A wedge-shaped plate (40) is provided in the sliding groove (4). The wedge-shaped plate (40) is provided with an abutting inclined surface. The abutting inclined surface gradually slopes downward along the direction pointing to the notch of the sliding groove (4); a push rod (43) is slidably arranged in the bottom plate (203) corresponding to the wedge-shaped plate (40). The bottom end of the push rod (43) abuts against the abutting inclined surface; the wedge-shaped plate (40) on one side of the first template (201) is connected to the first template (201), and the wedge-shaped plate (40) on one side of the second template (202) is connected to the second template (202).

5. The aluminum alloy low-pressure casting device according to claim 4, characterized in that, The abutting inclined surface includes a first inclined surface (41) and a second inclined surface (42). The first inclined surface (41) is closer to the notch of the sliding groove (4) than the second inclined surface (42). The inclination degree of the first inclined surface (41) is less than that of the second inclined surface (42).

6. The aluminum alloy low-pressure casting device according to claim 2, characterized in that, An air inlet (206) is provided in the lower half (212) of the liquid inlet.

7. The aluminum alloy low-pressure casting device according to claim 6, characterized in that, On the inner wall of the lower half (212) of the liquid inlet, an annular groove (213) is provided corresponding to the air inlet (206). The annular groove (213) includes a vertically annular arc surface (215) and a horizontally annular plane (214). The annular arc surface (215) faces the axis of the liquid inlet pipe (209), and the annular plane (214) is arranged downward.

8. The aluminum alloy low-pressure casting device according to claim 7, characterized in that, On the inner wall of the upper half (210) of the liquid inlet, a flow channel groove (211) is provided. The number of the flow channel grooves (211) is multiple, and the multiple flow channel grooves (211) are arranged at circumferential intervals; one end of the flow channel groove (211) away from the separation nozzle (208) is located in the inner wall of the upper half (210) of the liquid inlet.

9. An aluminum alloy low-pressure casting process using the aluminum alloy low-pressure casting device according to any one of claims 1 to 8, characterized in that, Including: S1. Preheat the molding module (2), and then spray the mold release agent; S2. Close the mold of the molding module (2) through the hydraulic system (1), and after closing the mold, introduce compressed gas at 50 kPa into the interior of the molding module (2) for pressure holding. If the pressure does not drop by more than 2 kPa after 5 minutes of pressure holding, it is considered qualified; S3. Melt the aluminum liquid, skim off the floating slag and detect the hydrogen content; it is required that the hydrogen content ≤ 0.15 mL / 100 g; S4. Pour the aluminum liquid processed in S3 into the holding furnace (3), and slowly pressurize through the pressurizing system; S5. After pressure molding, set the shape for 3 to 10 minutes and perform auxiliary cooling; S6. Release the pressure step by step according to the gradient; S7. Open the mold and take out the molded casting to complete the casting.

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