Aluminum alloy low-pressure casting device and process thereof

Abstract

The invention relates to the technical field of low-pressure casting, and particularly discloses an aluminum alloy low-pressure casting device and a process thereof.The aluminum alloy low-pressure casting device comprises a hydraulic system, a forming module, a heat preservation furnace, a pressurization system and a control system, the forming module comprises a lower module, a liquid inlet is formed in the bottom of the lower module, and the inner wall of the upper half portion of the liquid inlet is in an inverted cone shape; the inner wall of the lower half part is conical, and a separation binding opening is formed between the upper half part and the lower half part; a cooling assembly is arranged on the upper half portion, corresponding to the liquid inlet, of the lower module, and a heating assembly is arranged on the lower half portion, corresponding to the liquid inlet, of the lower module. By arranging the inverted cone structure and the positive cone structure, the whole liquid inlet is of a conic structure, so that molten aluminum needing to be cooled and molten aluminum needing to be heated are distinguished, the contact area of the two parts of molten aluminum is reduced as much as possible, mutual influence of the cooling part and the heating part is avoided to the maximum extent, and the separation effect is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of low-pressure casting, and in particular to an aluminum alloy low-pressure casting device and a process thereof. Background Art

[0002] Low-pressure casting machine is a general-purpose equipment for low-pressure casting of aluminum alloys. It can be widely used in the production of aluminum alloy castings in automobiles, motorcycles, instruments, textile machinery and aerospace industries. Low-pressure casting machine consists of a main machine, hydraulic system, molten pool holding furnace, liquid surface pressurization device, electrical control system and mold cooling system.

[0003] During the casting process, 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 gas pressure, the molten metal rises along the riser tube and smoothly enters the mold cavity through the gate, and the gas pressure on the liquid surface in the crucible is maintained until the casting is completely solidified. Then the gas pressure on the liquid surface is released, and the unsolidified molten metal in the riser tube flows back to the crucible, and then the mold is opened to form a casting. In actual production, some problems are found, namely, the casting in the mold cavity When the casting is cooled and formed, the molten metal at the outlet of the lower mold is cooled and solidified, and the molten metal in the riser tube should flow back to the holding furnace (crucible) when the casting is fully formed. Therefore, there will be solid and liquid molten metal near the top of the riser tube. If the temperature is too high, the cooling and forming of the casting will be slowed down; if the temperature is too low, the molten metal in the riser tube will solidify more and affect demolding. Therefore, it is necessary to provide a low-pressure casting machine that can take into account both 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 process to solve the above-mentioned problems.

[0005] To achieve the above purpose, the technical solution of this application is: In the first aspect, the present application provides an aluminum alloy low-pressure casting device, including a hydraulic system, a forming module, a heat preservation furnace, a pressurizing system and a control system, the forming module including a lower module, the bottom of the lower module is provided with a liquid inlet, the upper half of the inner wall of the liquid inlet is in an inverted cone shape, the lower half of the inner wall is cone-shaped, and a partition opening 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 on the lower half of the liquid inlet.

[0006] Preferably, the lower module includes a base plate, a liquid inlet pipe is provided on the base plate, and the liquid inlet port is arranged in the liquid inlet pipe; a separation groove is provided on the outer peripheral wall of the liquid inlet pipe corresponding to the separation bundle port, and the separation groove is configured to prevent heat exchange between the upper and lower halves of the liquid inlet port.

[0007] Preferably, a vibration part is provided in the separation groove.

[0008] Preferably, the lower mold assembly also includes a first template and a second template, and the first template and the second template are slidably arranged on the bottom plate in opposite directions; sliding grooves are provided on the sides of the bottom plate corresponding to the first template and the second template respectively, extending toward the inside of the bottom plate, and a wedge plate is provided in the sliding groove, and an abutment slope is provided on the wedge plate, and the abutment slope gradually tilts downward in the direction pointing to the notch of the sliding groove; a push rod is slidably provided in the bottom plate corresponding to the wedge plate, and the bottom end of the push rod abuts against the abutment slope; the wedge plate located on one side of the first template is connected to the first template, and the wedge plate located on one side of the second template is connected to the second template.

[0009] 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 relative to the second inclined surface, and the inclination degree of the first inclined surface is smaller than the inclination degree of the second inclined surface.

[0010] Preferably, the molding module also includes an upper module, an annular cavity is provided inside the upper module, and two groups of expansion blocks are radially slidably provided on the outer peripheral wall of the upper module, and the two groups of expansion blocks are symmetrically arranged, and an abutment rod is provided in one side of the expansion block located in the annular cavity, and a variable diameter rotating column is provided between the two abutment rods, one end of the variable diameter rotating column is connected to a spring, and the other end of the spring is connected to the transmission shaft of the motor.

[0011] Preferably, an air inlet is provided at the lower half of the liquid inlet.

[0012] Preferably, an annular groove is provided on the inner wall of the lower half of the liquid inlet corresponding to the air inlet, and the annular groove includes a vertical annular arc surface and a horizontal annular plane, the annular arc surface faces the axis of the liquid inlet pipe, and the annular plane is arranged downward.

[0013] Preferably, a flow channel groove is provided on the inner wall of the upper half of the liquid inlet, and the number of the flow channel grooves is multiple, and the multiple flow channel grooves are arranged at intervals in the circumferential direction; one end of the flow channel groove away from the partition port is located in the inner wall of the upper half of the liquid inlet.

[0014] On the second aspect, a low-pressure casting process for aluminum alloys using the above-mentioned low-pressure casting device for aluminum alloys is also provided, including S1, preheating the forming module, and then spraying a release agent; S2, closing the molding module through a hydraulic system, and after closing the mold, introducing 50kPa of compressed gas into the interior of the molding module to maintain the pressure. After maintaining the pressure for 5 minutes, the pressure drop does not exceed 2kPa, which indicates that it is qualified; S3, melting the molten aluminum, skimming off the scum and detecting the hydrogen content; the hydrogen content is required to be ≤0.15mL / 100g; S4, pouring the aluminum liquid processed in S3 into a holding furnace, and slowly pressurizing it through a pressurizing system; S5, after pressure molding, it continues to be fixed for 3 to 10 minutes, and auxiliary cooling is performed; S6, depressurizing step by step according to the gradient; S7, opening the mold and taking out the formed casting to complete the casting.

[0015] The aluminum alloy low-pressure casting device disclosed in the present application sets an inverted cone structure and a forward cone structure so that the liquid inlet is an overall conical structure, thereby distinguishing the aluminum liquid that needs to be cooled and the aluminum liquid that needs to be heated, so as to reduce the contact area between the two parts of the aluminum liquid as much as possible, thereby avoiding the mutual influence of the cooling part and the heating part to the greatest extent and ensuring the separation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a three-dimensional diagram of the lower mold structure in this application; Figure 3 This is a cross-sectional view of the lower mold structure in this application; Figure 4 for Figure 3 A partial enlarged schematic diagram in the middle; Figure 5 This is a top view of the lower mold structure in this application; Figure 6 for Figure 5 Middle AA section cutaway view; Figure 7 for Figure 5 Middle BB section cutaway view; Figure 8 This is a structural diagram of the insulation furnace in this application; Fig. 9 This is a schematic diagram of the structure of the upper module in this application; Fig.10 for Fig. 9 A partial enlarged schematic diagram of point B in the middle; Fig.11 This is a schematic diagram of the upper module in this application from another angle.

[0017] In the figure: 1. Hydraulic system; 2. Forming module; 201. First template; 202. Second template; 203. Bottom plate; 205. Partition groove; 206. Air inlet; 207. Cooling assembly; 208. Partition port; 209. Liquid inlet pipe; 210. Upper half; 21. Lower module; 211. Runner groove; 212. Lower half; 213. Annular groove; 214. Annular plane; 215. Annular arc surface; 22. Upper module; 220. Annular cavity; 3. Insulating furnace; 4. Sliding groove; 40. Wedge plate; 41. First inclined plane; 42. Second inclined plane; 43. Push rod; 5. Lifting pipe; 50. Resistance heating belt; 6. Expansion block; 60. Abutment rod; 61. Variable diameter rotating column; 610. Arc side; 611. Abutment plane; 62. Spring. DETAILED DESCRIPTION

[0018] The present application is now described in further detail in conjunction with the accompanying drawings. The accompanying drawings are simplified schematic diagrams, which only illustrate the basic structure of the present application in a schematic manner, and therefore only show the components related to the present application.

[0019] like Figures 1 to 4 As shown, in the first aspect, the present application provides an aluminum alloy low-pressure casting device, including a hydraulic system 1, a forming module 2, a holding furnace 3, a pressurizing system and a control system, 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 cone shape, and the inner wall of the lower half 212 is in a cone shape, and a partition opening 208 is formed between the upper half 210 and the lower half 212; a cooling component 207 is provided on the upper half 210 of the lower module 21 corresponding to the liquid inlet, and a heating component is provided on the lower half 212 corresponding to the liquid inlet.

[0020] The hydraulic system 1 is used to realize the opening and closing of the forming module 2, the holding furnace 3 is used to keep the aluminum liquid warm, the pressurizing system is used to pressurize the holding furnace 3 so that the aluminum liquid in the holding furnace 3 rises along the rising pipe 5, and 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 holding furnace 3, the pressurizing 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 repeated in this embodiment.

[0021] The forming module 2 includes a lower module 21, which is provided with a liquid inlet for docking with the riser 5; the inner wall of the liquid inlet is divided into two parts, the upper half 210 is divided into an inverted cone structure, and the lower half 212 is divided into a cone structure, and the two parts are completely connected, and a conical opening is formed at the connection position of the two parts, that is, a separation opening 208, to facilitate the subsequent solidification of the aluminum liquid in the upper half 210 and the reflux of the aluminum liquid in the lower half 212.

[0022] The upper half 210 and the lower half 212 are only distinguished in terms of orientation, which does not mean that the upper half 210 and the lower half 212 equally divide the entire liquid inlet.

[0023] The cooling assembly 207 is correspondingly arranged outside the upper half 210 to accelerate cooling, and the heating assembly is correspondingly arranged outside the lower half 212 to maintain the temperature of the aluminum liquid and assist reflux.

[0024] A resistance heating belt 50 is provided on the outside of the riser pipe 5 .

[0025] The cooling component 207 may be a circulating water cooling pipe, and the heating component may be a resistance heating belt 50 .

[0026] By setting an inverted cone structure and a positive cone structure, the liquid inlet is made into a cone-shaped structure as a whole, so that the aluminum liquid that needs to be cooled and the aluminum liquid that needs to be heated can be distinguished, so as to reduce the contact area of ​​the two parts of the aluminum liquid as much as possible, thereby avoiding the mutual influence of the cooling part and the heating part to the greatest extent and ensuring the separation effect.

[0027] In some further embodiments, the lower module 21 includes a base plate 203, a liquid inlet pipe 209 is provided on the base plate 203, and the liquid inlet is arranged in the liquid inlet pipe 209; a separation groove 205 is provided on the outer peripheral wall of the liquid inlet pipe 209 corresponding to the separation opening 208, and the separation groove 205 is configured to prevent heat exchange between the upper half 210 and the lower half 212 of the liquid inlet.

[0028] The lower mold assembly 21 includes a base plate 203, which is a part of the cavity formed by the enclosed mold. A liquid inlet pipe 209 is arranged at the lower part thereof, and the liquid inlet is located in the liquid inlet pipe 209. In order to avoid the heat conduction effect, a separation groove 205 is opened on the outer peripheral wall of the liquid inlet pipe 209. The separation groove 205 is an annular groove 213, and its cross-section can be triangular or rectangular, and the separation groove 205 corresponds to the separation beam 208 in the liquid inlet in the horizontal direction; under the action of the separation groove 205 and the separation beam 208, the cooling part and the heating part in the liquid inlet pipe 209 can be well separated, so that the degree of mutual influence between each other during heating and cooling will be reduced, thereby reducing the cooling time of the bottom part of the casting and increasing the reflux amount of aluminum liquid, taking into account both efficiency and cost.

[0029] In some further embodiments, a vibration portion is provided in the separation groove 205 .

[0030] A vibration part is provided in the partition groove 205, and the vibration part can be a piezoelectric ceramic actuator, which is used to apply a certain vibration to the liquid inlet pipe 209. Firstly, it can increase the reflux of aluminum liquid to avoid adhesion on the inner wall of the liquid riser 5; secondly, it can facilitate demolding of the casting after molding and avoid damage to the outer wall of the casting when demolding by mechanical force.

[0031] The piezoelectric ceramic actuator can be installed by bonding or by clamping.

[0032] It should be noted that piezoelectric ceramic actuators are widely used in the industrial field and are existing technologies, and their results and working principles are not described in detail in this embodiment.

[0033] In other embodiments, the vibration part may also be a vibration motor.

[0034] like Figures 5 to 8 As shown in some further embodiments, the lower mold assembly 21 also includes a first template 201 and a second template 202, and the first template 201 and the second template 202 are slidably arranged on the bottom plate 203 in opposite directions; sliding grooves 4 are extended toward the inside of the bottom plate 203 on the sides of the bottom plate 203 corresponding to the first template 201 and the second template 202 respectively, and a wedge plate 40 is provided in the sliding groove 4, and an abutting inclined surface is provided on the wedge plate 40, and the abutting inclined surface gradually tilts downward in the direction pointing to the notch of the sliding groove 4; a push rod 43 is slidably provided in the bottom plate 203 corresponding to the wedge plate 40, and the bottom end of the push rod 43 abuts against the abutting inclined surface; the wedge plate 40 located on one side of the first template 201 is connected to the first template 201, and the wedge plate 40 located on the side of the second template 202 is connected to the second template 202.

[0035] The first mold plate 201 and the second mold plate 202 can slide relatively close to or relatively far away from each other on the bottom plate 203 to achieve mold closing and mold opening.

[0036] The direction in which the first mold plate 201 opens is defined as a first direction, and the direction in which the second mold opens is defined as a second direction. The first direction is relative to and opposite to the second direction.

[0037] The side walls of the bottom plate 203 located on one side of the first direction and on the side located on the second direction are both provided with sliding grooves 4, and the sliding grooves 4 extend toward the inside of the bottom plate 203 correspondingly but do not penetrate the bottom plate 203, wherein the sliding grooves 4 located on one side of the liquid inlet on the two side walls are arranged alternately in sequence, that is, in the horizontal direction along the direction perpendicular to the first direction, they can be: the sliding groove 4 opening toward the first direction, the sliding groove 4 opening toward the second direction, and the sliding groove 4 opening toward the first direction.

[0038] A sliding hole is provided on the bottom plate 203, in which a push rod 43 is slidably provided. The sliding holes are all located directly above the sliding groove 4 and are interconnected with the sliding groove 4, and the push rod 43 is slidably provided in the sliding hole; a wedge plate 40 is slidably provided in the sliding groove 4, and the top of the wedge plate 40 is an inclined structure, that is, an abutting inclined surface, wherein the abutting inclined surface in the sliding groove 4 with an opening toward the first direction gradually tilts downward along the first direction, and the abutting inclined surface in the sliding groove 4 with an opening toward the second direction gradually tilts downward along the second direction, so as to ensure that the wedge plate 40 can continuously abut against the push rod 43 when sliding out of the sliding groove 4, so that the push rod 43 abuts against the formed casting to achieve demolding.

[0039] In addition, the wedge plates 40 located in the sliding grooves 4 opening in the first direction are connected to the first template 201, that is, when the first template 201 is opened along the first direction, the wedge plates 40 will be driven to move synchronously, thereby realizing the upward push of the casting synchronously during the mold opening process.

[0040] In traditional low-pressure casting machines, the ejection mechanism is usually set separately, and an independent driving structure needs to be set up additionally, and it often needs to occupy a part of the position below the molding 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 achieve synchronous triggering of the two. This avoids the setting of cumbersome PLC execution timing, ensures the stability of action execution, and also makes the structure of the entire device more streamlined.

[0041] 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 relative to the second inclined surface 42 , and the inclination degree of the first inclined surface 41 is smaller than the inclination degree of the second inclined surface 42 .

[0042] In order to ensure the stability of the abutment process, the wedge plate 40 abuts the push rod 43 in stages. Specifically, the abutment slope includes a first slope 41 and a second slope 42. The first slope 41 is closer to the notch of the sliding groove 4, and the inclination of the first slope 41 is less than that of the second slope 42. This ensures that when the wedge plate 40 slides from the sliding groove 4, the first slope 41 abuts the push rod 43 first, and then the second slope 42 abuts the push rod 43, thereby slowly releasing the initial adhesion between the casting and the mold to avoid local stress concentration, and then speeding up to reduce the demolding time.

[0043] like Figures 9 to 11As shown, in some further embodiments, the molding module 2 also includes an upper module 22, an annular cavity 220 is provided inside the upper module 22, and two groups of expansion blocks 6 are radially slidably provided on the outer peripheral wall of the upper module 22, and the two groups of expansion blocks 6 are symmetrically arranged, and an abutment rod 60 is provided in one side of the expansion block 6 located in the annular cavity 220, and a variable diameter rotating column 61 is provided between the two abutment 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.

[0044] When the upper die set 22 rises under the action of the hydraulic system 1, it will be driven to gradually rise synchronously, and then fall into the die removal mechanism through vibration or manual knocking.

[0045] In the present embodiment, in order to prevent the casting from accidentally falling off before the mold removal mechanism is in place, two groups of expansion blocks 6 are symmetrically arranged in the upper mold assembly 22. The two groups of expansion blocks 6 are slidably arranged along the central direction of the upper mold assembly 22, and abutment rods 60 are arranged on the side where the two groups of expansion blocks 6 face each other. The ends of the abutment rods 60 away from the expansion blocks 6 face each other but do not abut, and a variable diameter rotating column 61 is arranged in the area separated by the ends of the two abutment rods 60. In the initial state, the expansion blocks 6 do not slide and maintain balance under the abutment action of the abutment rods 60 and the variable diameter rotating column 61. When the variable diameter rotating column 61 rotates, the distance between the two abutment rods 60 becomes larger, so that the two groups of expansion blocks 6 move back to back, that is, the outer wall of the upper mold assembly 22 will appear slightly convex, thereby achieving a certain clamping of the casting to prevent the casting from falling off.

[0046] However, the two expansion blocks 6 may cause damage to the casting after sliding back to back. In order to solve this problem, a spring 62 is specially provided to make the expansion block 6 expand adaptively or flexibly. That is, the spring 62 is driven by a motor to rotate. The rotating spring 62 will generate a rotational force on the variable diameter rotating column 61 but it is not a mechanical hard rotation. As a result, the expansion block 6 generates more adaptive force of expansion and abutment on the casting, thereby avoiding certain damage to the casting.

[0047] The variable diameter rotating column 61 includes two arcuate side surfaces 610 and two abutting planes 611 . The two abutting planes 611 are used to ensure the stability of the two groups of expansion blocks 6 in the initial state, and the two arcuate side surfaces 610 are used to facilitate the rotation of the variable diameter rotating column 61 .

[0048] Please refer to Figure 4 As shown, in some further embodiments, the lower half 212 of the liquid inlet is provided with an air inlet 206 .

[0049] When the casting is demoulded after being formed, gas can be introduced into the air inlet 206 to increase the reflux of the aluminum liquid. At the same time, the air flow will also form a certain separation effect between the cooled and formed aluminum solid in the upper half 210 and the inner wall, so as to facilitate demoulding of the two and avoid damage to the casting under the action of mechanical force.

[0050] In order to prevent aluminum liquid from seeping out of the pores, a porous ceramic filter plate (porous ceramic with a slide rail) and a metal support mesh can be set in the air inlet.

[0051] 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, and the annular groove 213 includes a vertical annular arc surface 215 and a horizontal annular plane 214, the annular arc surface 215 faces the axis of the liquid inlet pipe 209, and the annular plane 214 is set downward.

[0052] 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 aluminum liquid from adhering to the inner wall.

[0053] 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.

[0054] In some further embodiments, a flow groove 211 is provided on the inner wall of the upper half 210 of the liquid inlet, and the number of the flow grooves 211 is multiple, and the multiple flow grooves 211 are arranged at intervals in the circumferential direction; one end of the flow groove 211 away from the separating bundle port 208 is located in the inner wall of the upper half 210 of the liquid inlet.

[0055] The flow channel groove 211 can increase the airflow entering between the inner wall of the upper half 210 and the solidified aluminum solid to a certain extent, so as to increase the force pushing the casting upward.

[0056] In the second aspect, a low-pressure casting process for aluminum alloys using the above-mentioned low-pressure casting device for aluminum alloys is also provided, including: S1, preheating the forming module 2, and then spraying a release agent; S2, closing the mold of the forming module 2 through the hydraulic system 1, and after closing the mold, introducing 50kpa of compressed gas into the inside of the forming module 2 to maintain the pressure. After maintaining the pressure for 5 minutes, the pressure drop does not exceed 2kpa, which indicates that it is qualified; S3, melting the molten aluminum, skimming the scum and detecting the hydrogen content; the hydrogen content is required to be ≤0.15mL / 100g; S4, pouring the aluminum liquid processed in S3 into the holding furnace 3, and slowly pressurizing it through the pressurizing system; S5, after the pressure is filled and molded, it is fixed for 3 to 10 minutes, and auxiliary cooling is performed; S6, the pressure is released step by step according to the gradient; S7, the mold is opened to take out the molded casting to complete the casting.

[0057] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled 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 methods here. The obvious changes or modifications derived from these are still within the scope of protection created by this application.

Claims

1. An aluminum alloy low-pressure casting device, comprising a hydraulic system (1), a forming module (2), a holding furnace (3), a pressurizing system and a control system, characterized in that: The molding module (2) comprises 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 the shape of an inverted cone, the inner wall of the lower half (212) is in the shape of a cone, and a partition opening (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 on the lower half (212) of the liquid inlet.

2. The aluminum alloy low pressure casting device according to claim 1, characterized in that: The lower module (21) comprises 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 separation groove (205) is provided on the outer peripheral wall of the liquid inlet pipe (209) corresponding to the separation bundle opening (208), and the separation groove (205) is arranged to prevent the upper half (210) and the lower half (212) of the liquid inlet from exchanging heat.

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

4. The aluminum alloy low pressure casting device according to claim 2, characterized in that: The lower mold assembly (21) further comprises a first mold plate (201) and a second mold plate (202), wherein the first mold plate (201) and the second mold plate (202) are arranged on the bottom plate (203) in a sliding manner in opposite directions; sliding grooves (4) are arranged on the sides of the bottom plate (203) corresponding to the first mold plate (201) and the second mold plate (202) and extending toward the inside of the bottom plate (203); a wedge plate (40) is arranged in the sliding groove (4), and a There is an abutment inclined surface, and the abutment inclined surface gradually tilts downward in a direction pointing to the notch of the sliding groove (4); a push rod (43) is provided in the bottom plate (203) corresponding to the sliding of the wedge plate (40), and the bottom end of the push rod (43) abuts against the abutment inclined surface; the wedge plate (40) located on one side of the first template (201) is connected to the first template (201), and the wedge plate (40) located 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 comprises 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) relative to the second inclined surface (42); and the inclination of the first inclined surface (41) is smaller than that of the second inclined surface (42).

6. The aluminum alloy low pressure casting device according to claim 1, characterized in that: The molding die set (2) further comprises an upper die set (22), an annular cavity (220) being provided inside the upper die set (22), two groups of expansion blocks (6) being radially slidably provided on the outer peripheral wall of the upper die set (22), the two groups of expansion blocks (6) being symmetrically arranged, an abutment rod (60) being provided on one side of the expansion block (6) located on the annular cavity (220), a variable diameter rotating column (61) being provided between the two abutment rods (60), one end of the variable diameter rotating column (61) being connected to a spring (62), and the other end of the spring (62) being connected to a transmission shaft of the motor.

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

8. The aluminum alloy low pressure casting device according to claim 7, characterized in that: 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) comprises a vertical annular arc surface (215) and a horizontal 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.

9. The aluminum alloy low pressure casting device according to claim 8, characterized in that: A flow channel groove (211) is provided on the inner wall of the upper half (210) of the liquid inlet, and 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) away from the partitioning port (208) is located in the inner wall of the upper half (210) of the liquid inlet.

10. A process for low-pressure casting of aluminum alloy using the low-pressure casting device of aluminum alloy as claimed in any one of claims 1 to 9, characterized in that: include: S1, preheating the molding module (2), and then spraying a release agent; S2. The molding module (2) is closed by the hydraulic system (1), and after closing the mold, 50 kPa of compressed gas is introduced into the molding module (2) to maintain the pressure. After maintaining the pressure for 5 minutes, if the pressure drops by no more than 2 kPa, it is considered qualified. S3, smelt aluminum liquid, skim off the scum and detect the hydrogen content; the hydrogen content is required to be ≤0.15mL / 100g; S4, pouring the aluminum liquid processed in S3 into the holding furnace (3), and slowly pressurizing it through a pressurizing system; S5, after the pressure molding, the molding is continued for 3 to 10 minutes, and auxiliary cooling is performed; S6, release pressure step by step according to the gradient; S7. Open the mold and take out the formed casting to complete the casting.

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