A large thin-walled aluminum alloy cavity vacuum pressure casting device and a method of using the same

Abstract

The present application relates to the technical fields of aluminum alloy manufacturing, and particularly relates to a large thin-walled aluminum alloy cavity vacuum pressure casting device and a use method thereof, which comprises a mounting frame, a first fixing frame and a vacuum adsorber are sequentially arranged on one side of the mounting frame, a fixed mold is arranged on one side of the first fixing frame, a second fixing frame is arranged on the other side of the mounting frame, and a sliding frame is jointly and slidably arranged on two positioning sliding rods; a heat exchange ejection assembly is arranged in the fixed mold; and a driving assembly is arranged on the mounting frame and the sliding frame. Compared with the prior art, the hollow ejection frame made of high-thermal-conductivity alloy is linked with the heat exchange system, so that the cold air flowing in the mold is instantaneously heated into hot air in the hot ejection frame during the ejection stage, the hot air is redirected and sprayed to the surface of the cavity during the reset return, and the in-situ uniform preheating is completed.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy manufacturing technology, and in particular to a large thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method. Background Technology

[0002] In the vacuum pressure casting production process of large thin-walled aluminum alloy cavities, in order to reduce the gas content in the cavity and avoid defects such as porosity and oxide inclusions in the casting, vacuum technology is generally used. That is, after mold closing and before injection, the air in the cavity and pressure chamber is evacuated to a high vacuum level (usually the absolute pressure is below 100mbar) before the molten metal is injected and filled.

[0003] In existing technologies, to ensure good fluidity of molten aluminum alloy when filling thin-walled cavities and to avoid defects such as cold shuts and incomplete filling caused by excessively low mold temperatures, the mold (especially the cavity surface) needs to be preheated to a relatively high and uniform working temperature (usually about 150-200°C) before production. Currently, this preheating process mainly relies on external gas heaters, electric heating tubes, or hot oil heaters to heat the mold. This active heating method has huge power and extremely high energy consumption. More paradoxically, after each casting cycle, the casting ejected from the mold carries a large amount of high-temperature residual heat (usually as high as 300-400°C). This heat is not only not effectively utilized, but also needs to be forcibly removed through a cooling system (such as a water cooling channel) to restore the mold temperature to a controllable range, which consumes additional cooling energy. The entire process presents a paradox of "high-energy preheating" and "high-energy cooling", resulting in extremely low overall energy utilization efficiency.

[0004] Secondly, there is the conflict between production cycle and energy consumption. Preheating and heat preservation of the mold is a process that continuously consumes energy. In continuous production, if it is necessary to change the mold or process parameters, the aforementioned external heating equipment must work continuously to maintain the mold temperature. Otherwise, after the mold cools down, it will require a longer reheating time, which will seriously slow down the production cycle. Therefore, in order to ensure production efficiency, it is necessary to accept continuous high energy consumption. Therefore, this application discloses a large thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a large-scale thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method, so as to solve the paradox of energy waste caused by the coexistence of "high-energy-consuming mold preheating" to ensure quality and "high-energy-consuming casting cooling" to maintain production, and the problem of irreconcilable conflict between production cycle and continuous energy consumption input.

[0006] To achieve the above objectives, the present invention provides a large-scale thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method, comprising a mounting frame, wherein a first fixed frame and a vacuum adsorber are sequentially arranged on one side of the mounting frame, a fixed mold is arranged on one side of the first fixed frame, an adsorption tube is arranged on one side of the vacuum adsorber, and the other end of the adsorption tube is connected to the fixed mold, a second fixed frame is arranged on the other side of the mounting frame, two positioning slide rods are arranged at the bottom of the interior of the second fixed frame, a sliding frame is slidably mounted on the two positioning slide rods, a hydraulic rod is fixedly mounted on the other end of the mounting frame, the telescopic end of the hydraulic rod is fixedly connected to one side of the sliding frame, a mounting block is arranged on one side of the sliding frame, and a movable mold is vertically slidably mounted on one side of the mounting block, the movable mold being arranged opposite to the fixed mold;

[0007] A heat exchange ejection assembly is disposed inside the fixed mold. The heat exchange ejection assembly is used to eject the aluminum alloy product after die casting and to absorb and exchange heat during die casting.

[0008] An air intake assembly is disposed at the bottom of the fixed mold. The air intake assembly is used to inject external gas into the heat exchange ejection assembly for gas heating.

[0009] An exhaust module is disposed inside the heat exchange ejector assembly. The exhaust module is used to inject the gas after heat exchange into the fixed mold for preheating treatment.

[0010] A drive assembly is disposed on the mounting bracket and the sliding bracket. The drive assembly is used to drive the heat exchange ejection assembly to eject the finished product and to drive the air intake assembly to inject gas into the heat exchange ejection assembly.

[0011] Preferably, the heat exchange ejection assembly includes an ejector frame embedded inside the fixed mold, the ejector frame being connected to the fixed mold by a plurality of first return springs, the ejector frame being hollow inside, the ejector frame being made of a high thermal conductivity alloy, and the gas from the air intake assembly entering the interior of the ejector frame for heat exchange processing.

[0012] Preferably, the air intake assembly includes a housing fixedly installed at the bottom of the fixed mold. Two air intake cylinders are disposed within the housing. A crank is rotatably mounted at the bottom of the housing, and pistons are respectively disposed on the crank. The pistons are disposed inside the two air intake cylinders. An air chamber is disposed above each air intake cylinder, and air intake pipes are disposed on both sides of the air chamber for drawing in air. Two air outlet pipes are disposed at the top of the air chamber for discharging air. One-way valves are disposed inside both the air intake and air outlet pipes. Air inlets are provided on both sides of the fixed mold to match the air intake pipes. A connecting pipe is disposed at the top of the air outlet pipe and connects to the ejector frame.

[0013] Preferably, the driving assembly includes a positioning plate fixedly installed on one side of the mounting bracket. The positioning plate has a Z-shaped sliding groove. A vertical rod is provided on one side of the sliding bracket, and a connecting seat is slidably installed on the vertical rod. A sliding column is provided on one side of the connecting seat, and the sliding column is slidably installed inside the sliding groove. When the sliding bracket moves away from the fixed mold, the connecting seat moves upward under the drive of the sliding column. When the sliding bracket moves closer to the fixed mold, the connecting seat moves downward under the drive of the sliding column. A first connecting rod is provided on one side of the connecting seat, and a second connecting rod is rotatably installed on the other side of the first connecting rod. A sliding plate is slidably installed at the bottom of the fixed mold, and one side of the sliding plate is rotatably connected to the second connecting rod.

[0014] Preferably, a positioning chamber is provided on the side of the fixed mold away from the movable mold. An installation plate is fixedly installed inside the positioning chamber. A sliding groove is provided on the top of the installation plate. A sliding drive plate is slidably installed inside the sliding groove of the installation plate. The sliding drive plate is Z-shaped. The other side of the sliding drive plate is fixedly connected to the ejector frame. A rotating rod is also rotatably installed on one side of the installation plate. A second meshing gear is provided at the bottom of the rotating rod. A plurality of second meshing teeth are provided on one side of the sliding plate to mesh with the second meshing gear. A cam is fixedly sleeved on the top of the rotating rod. When the rotating rod rotates, it drives the cam to push the sliding drive plate to move. The sliding drive plate synchronously drives the ejector frame to eject outward.

[0015] Preferably, a second return spring is provided on one side of the sliding drive plate, and the other side of the second return spring is connected to the inner side of the slide groove.

[0016] Preferably, a first meshing gear is fixedly sleeved on one side of the crank, and a plurality of first meshing teeth are provided on the top surface of the middle part of the sliding plate to mesh with the first meshing gear.

[0017] Preferably, a second sealing plate is slidably installed on both sides of the fixed mold. The cross-section of the second sealing plate is L-shaped, and one side of the second sealing plate is fixedly connected to the sliding plate. When the movable mold is demolded, the second sealing plate opens the air inlet.

[0018] Preferably, the venting module includes a plurality of venting holes formed on the side of the ejector frame near the movable mold. A plurality of first sealing plates adapted to the venting holes are slidably installed inside the ejector frame. A plurality of auxiliary plates are fixedly installed inside the fixed mold. A trigger block is provided at the center of the top surface of each of the auxiliary plates. The trigger block is trapezoidal in shape. A plurality of third return springs are provided on the top of the first sealing plates. The other side of each of the third return springs is fixedly connected to one side of the ejector frame. When the ejector frame ejects outward or returns inward, the first sealing plate moves upward first under the drive of the trigger block, opening the venting holes. Then, under the drive of the third return springs, it returns to its original position, closing the venting holes. After returning to its original position, the ejector frame is flush with one side of the auxiliary plates. During ejection, gas is ejected from the venting holes to assist the ejector frame in ejecting the finished product. During return, the gas ejected from the venting holes, after heat exchange, preheats the interior of the fixed mold.

[0019] This invention also discloses a method for vacuum pressure casting of large thin-walled aluminum alloy cavities, applied to the aforementioned vacuum pressure casting apparatus for large thin-walled aluminum alloy cavities, comprising the following steps:

[0020] S1: The hydraulic rod drives the sliding frame to move backward, causing the movable mold to separate from the fixed mold; at the same time, the sliding plate moves outward, the L-shaped sealing plate opens the air inlet, and external air begins to enter the air intake assembly.

[0021] S2: The movement of the sliding plate drives the crank-piston mechanism to create negative pressure in the air chamber to draw in cold air. Then, during the reverse movement, the air is compressed and pushed into the hollow top ejector.

[0022] S3: The cam mechanism drives the sliding drive plate to push the ejector frame upward to eject the casting; the air vents on the surface of the ejector frame open under the action of the trigger block, and the airflow forms an air cushion to reduce friction and protect the mold surface.

[0023] S4: During the ejection process, compressed air flows inside the high-temperature ejection frame and is rapidly heated into hot air. The hot air is temporarily stored in the exhaust module after ejection is completed.

[0024] S5: The sliding frame moves forward, and the crank-piston mechanism moves again, injecting a metered amount of heated hot air into the cavity surface to achieve uniform preheating of the mold in a localized area. At the same time, the sealing plate closes the air inlet.

[0025] S6: The ejector and vent holes are reset and sealed tightly under the action of the spring to ensure the cavity is sealed; the vacuum adsorber is started to draw the cavity to a high vacuum state, completing the preheating and venting closed loop, and preparing for the next casting cycle.

[0026] The beneficial effects of this invention are:

[0027] 1. This large-scale thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method, by setting up a hollow ejector frame made of high thermal conductivity alloy in conjunction with the heat exchange system, allows the cold air flowing through the mold during the ejection stage to be instantly heated into hot air inside the hot ejector frame. During the return stroke, the hot air is then directed and sprayed onto the cavity surface to complete in-situ uniform preheating. This allows the residual heat carried by the casting from the previous mold to be directly reused in the preheating of the cavity of the next mold, constructing a closed-loop energy reuse path that does not rely on an external heat source. This structure does not continuously supply air to the cavity. The air outlet is only opened momentarily by the trigger block during the ejection and return paths, and is tightly sealed by the first sealing plate during the rest of the time. This avoids vacuum disruption and significantly reduces the energy consumption of external preheating and forced cooling, achieving both energy saving and cycle time with "less heating, less cooling, and faster reheating".

[0028] 2. This large-scale thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method, by setting up an air intake component, automatically draws in air during the demolding retraction stroke and automatically presses in during the mold closing forward stroke, quantitatively delivering cold air into the ejector frame for heat exchange without the need for a motor blower or external control; the L-shaped second sealing plates on both sides are linked to the air intake holes to open / close, ensuring that the cavity in front of the vacuum window is completely sealed and does not conflict with the vacuum system; this self-driven air circuit synchronizes "air intake-heat exchange-heat delivery" with the die casting cycle hardware, reducing the standby and repeated start-stop losses of independent heating equipment, alleviating the paradox of "high energy consumption preheating vs. high energy consumption cooling", and improving the mold temperature recovery speed and batch consistency.

[0029] 3. This large-scale thin-walled aluminum alloy cavity vacuum pressure casting device and its usage method, through the setting of ejection / reset kinematics formed by "cam-Z-shaped sliding drive plate-ejector frame" and the timing opening and closing mechanism of "trigger block-first sealing plate-vent hole-third reset spring", opens the vent hole in the initial stage of ejection to spray room temperature gas to form a micro air cushion, which significantly reduces the risk of demolding friction and scratches, protects the thin-walled surface and reduces ejection marks; when the reset return stroke is briefly opened again, the already heated hot air is sprayed to uniformly warm up the local overcooled areas, suppressing cold shuts, incomplete filling and dimensional drift caused by uneven mold temperature; after reset and positioning, the vent hole automatically closes, and the mold closing and vacuuming are not affected; this integrated sequence of "pneumatic assisted demolding + instantaneous preheating + sealing self-reset" unifies quality improvement, energy saving and vacuum process compatibility into a single mechanical link, ensuring long-term stable production. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0032] Figure 2 This is a schematic diagram of the planar structure of the present invention;

[0033] Figure 3 This is a schematic diagram of a partial planar structure of the present invention in the mold-closed state;

[0034] Figure 4 This is a schematic diagram of a partial planar structure of the present invention in its demolded state;

[0035] Figure 5 For the present invention Figure 3 Enlarged structural diagram at point A in the middle;

[0036] Figure 6 For the present invention Figure 4 Enlarged structural diagram at point B;

[0037] Figure 7 This is a schematic diagram of the positioning plate, sliding groove, and sliding column structure of the present invention;

[0038] Figure 8 This is a schematic diagram of the mold closing three-dimensional structure of the present invention;

[0039] Figure 9 This is a three-dimensional structural diagram of the air intake assembly of the present invention;

[0040] Figure 10 This is a schematic cross-sectional view of the air intake assembly of the present invention;

[0041] Figure 11 This is a schematic diagram of the fixed mold structure of the present invention;

[0042] Figure 12 This is a schematic diagram of the heat exchange pop-out component structure of the present invention;

[0043] Figure 13 This is a partial structural diagram of the heat exchange pop-out component of the present invention;

[0044] Figure 14 For the present invention Figure 13 Enlarged structural diagram at point C;

[0045] Figure 15 This is a schematic diagram of the air outlet module structure of the present invention.

[0046] The diagram is marked as follows:

[0047] 1. Mounting bracket; 2. First fixed bracket; 3. Fixed mold; 4. Vacuum adsorber; 5. Adsorption tube; 6. Second fixed bracket; 7. Positioning slide rod; 8. Mounting block; 9. Hydraulic rod; 10. Movable mold; 11. Sliding frame; 12. Positioning plate; 13. Sliding groove; 14. Vertical rod; 15. Connecting seat; 16. First connecting rod; 17. Second connecting rod; 18. Sliding plate; 19. First meshing gear; 20. Housing; 21. Crank; 22. Piston; 23. First meshing gear; 24. 25. Air chamber; 26. Air inlet pipe; 27. Air outlet pipe; 28. Sliding column; 29. ​​Air inlet; 30. Ejector frame; 31. First return spring; 32. Positioning chamber; 33. Mounting plate; 34. Sliding drive plate; 35. Second return spring; 36. Rotating rod; 37. Second meshing gear; 38. Second meshing teeth; 39. Cam; 40. Air outlet; 41. Auxiliary plate; 42. Trigger block; 43. First sealing plate; 44. Third return spring; 45. Connecting pipe; 46. Second sealing plate. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0049] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0050] like Figures 1 to 15As shown, a large thin-walled aluminum alloy cavity vacuum pressure casting device includes a mounting frame 1. A first fixed frame 2 and a vacuum adsorber 4 are sequentially arranged on one side of the mounting frame 1. A fixed mold 3 is arranged on one side of the first fixed frame 2. An adsorption tube 5 is arranged on one side of the vacuum adsorber 4, and the other end of the adsorption tube 5 is connected to the fixed mold 3. A second fixed frame 6 is arranged on the other side of the mounting frame 1. Two positioning slide rods 7 are arranged at the bottom of the interior of the second fixed frame 6. A sliding frame 11 is slidably mounted on the two positioning slide rods 7. A hydraulic rod 9 is fixedly mounted on the other end of the mounting frame 1. The telescopic end is fixedly connected to one side of the sliding frame 11. A mounting block 8 is provided on one side of the sliding frame 11, and a movable mold 10 is vertically slidably mounted on one side of the mounting block 8. The movable mold 10 is positioned opposite to the fixed mold 3. A heat exchange ejection assembly is located inside the fixed mold 3. The heat exchange ejection assembly is used to eject the molded aluminum alloy product and absorb and exchange heat during the molding process. An air intake assembly is located at the bottom of the fixed mold 3. The air intake assembly is used to inject external gas into the heat exchange ejection assembly for gas heating. An air outlet module is used for air outlet. The module is located inside the heat exchange ejection assembly. The air outlet module is used to inject the gas after heat exchange into the fixed mold 3 for preheating treatment. The drive assembly is set on the mounting frame 1 and the sliding frame 11. The drive assembly is used to drive the heat exchange ejection assembly to eject the finished product and to drive the air inlet assembly to inject gas into the heat exchange ejection assembly. The drive assembly includes a positioning plate 12 fixedly installed on one side of the mounting frame 1. The positioning plate 12 has a Z-shaped sliding groove 13. A vertical rod 14 is provided on one side of the sliding frame 11. A connecting seat 15 is slidably installed on the vertical rod 14. A sliding column 28 is provided on one side of the connecting seat 15. The sliding column 28 is slidably installed inside the sliding groove 13. When the sliding frame 11 moves away from the fixed mold 3, the connecting seat 15 moves upward under the drive of the sliding column 28. When the sliding frame 11 moves closer to the fixed mold 3, the connecting seat 15 moves downward under the drive of the sliding column 28. A first connecting rod 16 is provided on one side of the connecting seat 15. A second connecting rod 17 is rotatably installed on the other side of the first connecting rod 16. A sliding plate 18 is slidably installed at the bottom of the fixed mold 3. One side of the sliding plate 18 is rotatably connected to the second connecting rod 17.

[0051] The entire system's workflow begins after a casting cycle ends and the mold is opened and ejected: the hydraulic rod 9 is activated, pulling the sliding frame 11 backward (away from the fixed mold 3) along the positioning slide rod 7, causing the movable mold 10 to open; at this time, the vertical rod 14 fixed on the sliding frame 11 and its connecting seat 15 retract together. Since the sliding column 28 on the connecting seat 15 is stuck in the fixed Z-shaped sliding groove 13, this retraction action forces the sliding column 28 to move along the inclined side of the Z-shaped groove, thereby pushing the connecting seat 15 upward; the upward movement of the connecting seat 15 is converted into a pulling force on the sliding plate 18 through the first connecting rod 16 and the second connecting rod 17, causing the sliding plate 18 to slide away from the fixed mold 3; this action of the sliding plate 18 will drive the air intake assembly connected to it, injecting a stream of cold air into the heat exchange ejection assembly (at this time, it is ejected). In the casting process (where the casting is in a high-temperature state), cold air is rapidly heated into hot air and temporarily stored. Subsequently, hydraulic rod 9 pushes sliding frame 11 to carry movable mold 10 forward to begin mold closing. Vertical rod 14 and connecting seat 15 move forward accordingly. Sliding column 28, under the reverse action of Z-groove, pushes connecting seat 15 downward, and then pushes sliding plate 18 into the fixed mold 3 through connecting rod assembly. This action of sliding plate 18 drives air outlet module to blow the previously stored hot air to the cavity surface of fixed mold 3 (this action is completed before vacuum adsorption) to preheat it. After preheating, movable mold 10 and fixed mold 3 are completely closed. Vacuum adsorber 4 is activated and all gas (including residual hot air) in the cavity is extracted through adsorption pipe 5 to establish a pure vacuum environment. Then, the next injection filling can be carried out to start a new casting cycle.

[0052] like Figures 3 to 8 , Figures 11 to 13As shown, the heat exchange ejection assembly includes an ejector frame 30 embedded inside the fixed mold 3. Several first return springs 31 connect the ejector frame 30 to the fixed mold 3. The ejector frame 30 is hollow and made of a high thermal conductivity alloy. Gas from the air intake assembly enters the ejector frame 30 for heat exchange. A positioning chamber 32 is located on the side of the fixed mold 3 away from the movable mold 10. A mounting plate 33 is fixedly installed inside the positioning chamber 32. A groove is formed on the top of the mounting plate 33, and a sliding drive plate 34 is slidably installed inside the groove. The sliding drive plate 34 is Z-shaped. The other side of the sliding drive plate 34 is fixedly connected to the ejector frame 30. A rotating rod 36 is rotatably mounted on one side of the mounting plate 33. A second meshing gear 37 is provided at the bottom of the rotating rod 36. A number of second meshing teeth 38 are provided on one side of the sliding plate 18 to mesh with the second meshing gear 37. A cam 39 is fixedly sleeved on the top of the rotating rod 36. When the rotating rod 36 rotates, the driving cam 39 pushes the sliding drive plate 34 to move. The sliding drive plate 34 synchronously drives the ejector frame 30 to push outward. A second return spring 35 is provided on one side of the sliding drive plate 34. The other side of the second return spring 35 is connected to the inside side of the slide groove.

[0053] When the sliding plate 18 slides horizontally inside the fixed mold 3, the second meshing teeth 38 on its side drive the second meshing gear 37 that meshes with it to rotate, thereby driving the cam 39 fixedly mounted on the top of the same rotating rod 36 to rotate synchronously; the protruding part of the rotating cam 39 presses against the Z-shaped sliding drive plate 34, pushing it to slide along the slide groove on the mounting plate 33. When demolding, it will drive the ejector 30 to be ejected. At this time, the cold air injected by the air intake assembly is flowing through the hot hollow ejector 30 (wherein, the ejector 30 is made of a high thermal conductivity metal material, and its thermal conductivity at 20°C is not less than 200W / (m·K)). Preferably, the thermal conductivity is 280–380 W / (m·K); and the high thermal conductivity material can be copper chromium zirconium alloy (CuCrZr), dispersion-strengthened copper, or equivalent alternative materials), which is heated into high-temperature hot air; after ejection, the drive assembly drives the sliding plate 18 to slide in the opposite direction, and its teeth drive the gear and cam 39 to reverse. The pressure of cam 39 on sliding drive plate 34 is released. Under the combined rebound action of first return spring 31 and second return spring 35, sliding drive plate 34 and ejector 30 quickly reset together and return to their original position in the cavity, preparing for the next casting cycle. When the mold is closed, the reverse drive drives the ejector 30 to reset and fit.

[0054] like Figures 3 to 10As shown, the air intake assembly includes a housing 20 fixedly installed at the bottom of the fixed mold 3. Two air intake cylinders are disposed within the housing 20. A crank 21 is rotatably mounted at the bottom of the housing 20, and pistons 22 are respectively disposed on the crank 21. The pistons 22 are disposed inside the two air intake cylinders. An air chamber 24 is disposed above the air intake cylinders. Air intake pipes 25 are disposed on both sides of the air chamber 24 for drawing in air. Two air outlet pipes 26 are disposed at the top of the air chamber 24 for discharging air. One-way valves are disposed inside both the air intake pipes 25 and the air outlet pipes 26. Both sides are provided with air inlets 29 that are adapted to air inlets 25. The top of the air outlet pipe 26 is provided with a connecting pipe 45 that is connected to the ejector frame 30. A first meshing gear 23 is fixedly sleeved on one side of the crank 21. Several first meshing teeth 19 are provided on the top surface of the middle part of the sliding plate 18 to mesh with the first meshing gear 23. A second sealing plate 46 is slidably installed on both sides of the fixed mold 3. The cross-section of the second sealing plate 46 is L-shaped, and one side of the second sealing plate 46 is fixedly connected to the sliding plate 18. When the movable mold 10 is demolded, the second sealing plate 46 opens the air inlet 29.

[0055] When the movable mold 10 is demolded and the sliding frame 11 drives the sliding plate 18 to retreat away from the fixed mold 3, the sliding plate 18 first opens the air inlets 29 on both sides of the fixed mold 3 through the L-shaped second sealing plate 46 fixed to it, allowing external air to enter; then, the first meshing tooth 19 in the middle of the sliding plate 18 drives the first meshing gear 23 to rotate, driving the crank 21 to rotate; the rotation of the crank 21 pushes the two pistons 22 to reciprocate in their respective air inlets; the movement of the pistons 22 generates negative pressure in the air chamber 24, and external cold air enters through the opened air inlets 29 and air inlets 25 ( At this time, the one-way valve of the air inlet pipe 25 is opened and the air is drawn into the air chamber 24. Subsequently, when the movable mold 10 closes and the sliding plate 18 moves into the fixed mold 3, the first meshing tooth 19 drives the gear and crank 21 to reverse again, pushing the piston 22 to compress the cold air drawn into the air chamber 24 and push open the one-way valve in the air outlet pipe 26. This metered amount of cold air is forced into the hollow ejector frame 30, which is in a high-temperature state, through the connecting pipe 45 for heat exchange. At the same time, the forward movement of the sliding plate 18 also pushes the L-shaped second sealing plate 46 to close the air inlet 29, preparing for the sealing in the subsequent vacuuming and injection stages.

[0056] like Figures 13 to 15As shown, the venting module includes several vent holes 40 on the side of the ejector frame 30 near the movable mold 10. Several first sealing plates 43 adapted to the vent holes 40 are slidably installed inside the ejector frame 30. Several auxiliary plates 41 are fixedly installed inside the fixed mold 3. A trigger block 42 is provided in the middle of the top surface of the auxiliary plates 41. The trigger block 42 is trapezoidal. Several third return springs 44 are provided on the top of the first sealing plates 43. The other side of the third return springs 44 is connected to the ejector frame 3. The internal side of the mold 3 is fixedly connected. When the ejector 30 is ejected outward or reset inward, the first sealing plate 43 moves upward first under the drive of the trigger block 42, opening the vent 40. Then, under the drive of the third reset spring 44, it resets and closes the vent 40. After the ejector 30 is reset, it is flush with one side of the auxiliary plate 41. When ejecting, the vent 40 sprays gas to assist the ejector 30 in ejecting the finished product. When resetting, the vent 40 sprays gas after heat exchange to preheat the inside of the fixed mold 3.

[0057] When the ejector 30 is ejected from the cavity by the drive mechanism, its internal first sealing plate 43 moves accordingly. At the initial stage of the ejection stroke, the bottom of the first sealing plate 43 slides over the inclined surface of the trapezoidal trigger block 42 above. The inclined surface of the trigger block 42 forces the first sealing plate 43 to compress the third return spring 44 and lift it upwards, thereby opening the vent 40 on the surface of the ejector 30. At this time, the gas flowing inside the ejector 30 is instantly ejected downwards from the vent 40. This airflow forms a tiny "air cushion" between the casting and the mold cavity, effectively reducing ejection friction, achieving pneumatically assisted demolding, and protecting the mold surface and the integrity of the casting. After the ejection action is completed, the ejector 30 begins to reset and retracts into the cavity. When the first... When the sealing plate 43 passes the trigger block 42 again, the above process will be repeated, and the vent 40 will be opened again. However, at this time, the ejector frame 30 is filled with heated high-temperature hot air. The hot air is sprayed out from the vent 40 and blows directly onto the surface of the cavity, which has just been demolded and has a relatively low temperature, to preheat it evenly and prepare it for the next die casting, thus achieving precise in-situ energy recovery. When the ejector frame 30 is fully reset to be flush with the auxiliary plate 41, the first sealing plate 43 completely leaves the range of action of the trigger block 42 and falls rapidly under the elastic force of the third reset spring 44, sealing the vent 40 tightly. This ensures that when the mold is closed and vacuumed later, the cavity becomes a completely sealed independent system, guaranteeing the process requirements of vacuum die casting. This completes a full work cycle.

[0058] This invention also discloses a method for vacuum pressure casting of large thin-walled aluminum alloy cavities, applicable to a large thin-walled aluminum alloy cavity vacuum pressure casting device, comprising the following steps:

[0059] S1: The hydraulic rod 9 drives the sliding frame 11 to move backward, causing the movable mold 10 to separate from the fixed mold 3; at the same time, the sliding plate 18 moves outward, and the L-shaped sealing plate opens the air inlet 29, allowing external air to enter the air intake assembly;

[0060] S2: The movement of the sliding plate 18 drives the crank 21-piston 22 mechanism to act, creating a negative pressure in the air chamber 24 to draw in cold air. Then, during the reverse movement, the air is compressed and pushed into the hollow top ejector 30.

[0061] S3: The cam 39 mechanism drives the sliding drive plate 34 to push the ejector 30 upward to eject the casting; the air outlet 40 on the surface of the ejector 30 opens under the action of the trigger block 42, spraying out airflow to form an air cushion, reducing friction and protecting the mold surface;

[0062] S4: During the ejection process, compressed air flows inside the high-temperature ejection frame 30 and is rapidly heated into hot air. The hot air is temporarily stored in the exhaust module after ejection is completed.

[0063] S5: The sliding frame 11 moves forward, and the crank 21-piston 22 mechanism moves again, injecting the heated hot air into the cavity surface in a metered manner to achieve uniform preheating of the mold in a local area. At the same time, the sealing plate closes the air inlet 29.

[0064] S6: The ejector 30 and the vent 40 are reset and sealed tightly under the action of the spring to ensure the cavity is sealed; the vacuum adsorber 4 is started to draw the cavity to a high vacuum state, complete the preheating and degassing closed loop, and prepare for the next casting cycle.

[0065] Compared with existing technologies, by introducing the coordinated operation of heat exchange ejection components, air intake components, and air exhaust modules during the ejection and mold closing processes, a cyclical process of automatic cold air intake, compression, heating, and quantitative hot air injection is achieved. This allows an air cushion to be formed during the ejection of the casting to assist in demolding, reducing friction and damage. Furthermore, the excess heat from the ejection frame is converted into hot air for mold preheating in the next cycle. This avoids the paradox of "high-energy preheating + high-energy cooling" in traditional processes, which rely on external heaters for high-energy preheating and then water cooling to forcibly remove residual heat. It truly achieves in-situ energy recovery and closed-loop utilization, significantly reducing overall energy consumption and increasing production cycle time. At the same time, it ensures the sealing and vacuum level of the cavity during the vacuuming stage, avoiding damage to the process environment, and balancing energy saving, efficiency, and product quality.

[0066] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0067] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A large thin-walled aluminum alloy cavity vacuum pressure casting apparatus characterized by, The utility model relates to a kind of aluminum alloy product casting machine, including: Mounting frame (1), one side of the mounting frame (1) is sequentially provided with first fixed frame (2) and vacuum adsorber (4), one side of the first fixed frame (2) is provided with fixed mould (3), one side of the vacuum adsorber (4) is provided with suction tube (5), the other end of the suction tube (5) is communicated with the fixed mould (3), the other side of the mounting frame (1) is provided with second fixed frame (6), the inside bottom of the second fixed frame (6) is provided with two positioning slide rods (7), two the positioning slide rods (7) are slidably installed with sliding frame (11) in common, the other end of the mounting frame (1) is fixedly installed with hydraulic rod (9), the telescopic end of the hydraulic rod (9) is fixedly connected with one side of the sliding frame (11), one side of the sliding frame (11) is provided with mounting block (8), the mounting block (8) one side is vertically slidably installed with movable mould (10), the movable mould (10) is oppositely arranged with the fixed mould (3); Heat exchange ejection assembly, the heat exchange ejection assembly is arranged in the inside of the fixed mould (3), the heat exchange ejection assembly is used to eject after moulding aluminium alloy product and absorbs heat when moulding, the heat exchange ejection assembly includes ejector frame (30) embeddedly installed in the inside of the fixed mould (3); Air inlet assembly, the air inlet assembly is arranged in the bottom of the fixed mould (3), and the air inlet assembly is used to inject external gas into heat exchange ejection assembly, and gas heating is carried out; Air outlet module, the air outlet module is arranged in the inside of the heat exchange ejection assembly, and the air outlet module is used to inject the gas after heat exchange into the inside of the fixed mould (3), and preheating treatment is carried out; Driving assembly, the driving assembly is arranged on the mounting frame (1) and the sliding frame (11), and the driving assembly is used to drive the heat exchange ejection assembly to eject finished product, and the air inlet assembly is used to inject gas into heat exchange ejection assembly; The air outlet module comprises a plurality of air outlet holes (40) formed on one side of the ejection frame (30) close to the movable mold (10), a plurality of first sealing plates (43) adapted to the air outlet holes (40) are slidingly installed inside the ejection frame (30), a plurality of auxiliary plates (41) are fixedly installed inside the fixed mold (3), trigger blocks (42) are arranged in the middle of the top surface of the auxiliary plates (41), the trigger blocks (42) are arranged in a trapezoidal shape, a plurality of third return springs (44) are arranged on the top of the first sealing plates (43), one side of the third return springs (44) is fixedly connected to one side of the inside of the ejection frame (30), when the ejection frame (30) is ejected outward or reset inward, on the path, the first sealing plates (43) are first moved upward under the drive of the trigger blocks (42) to open the air outlet holes (40), and then reset to close the air outlet holes (40) under the drive of the third return springs (44), the ejection frame (30) is flush with one side of the auxiliary plates (41) after resetting, when ejecting, the air outlet holes (40) spray gas to assist the ejection frame (30) to eject the finished product, when resetting, the air outlet holes (40) spray the heat-exchanged gas to preheat the inside of the fixed mold (3).

2. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus according to claim 1, characterized by, A plurality of first return springs (31) are arranged between the ejection frame (30) and the fixed mold (3), the inside of the ejection frame (30) is hollow, the ejection frame (30) is made of high-thermal-conductivity alloy, and the gas of the air inlet assembly enters the inside of the ejection frame (30) for heat exchange treatment.

3. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus according to claim 2, characterized by, The air inlet assembly comprises a housing (20) fixedly installed at the bottom inside the fixed mold (3), two air inlet cylinders are arranged in the housing (20), a crank (21) is rotatably installed at the bottom inside the housing (20), pistons (22) are arranged on the crank (21), the pistons (22) are arranged in the two air inlet cylinders, an air chamber (24) is arranged above the air inlet cylinders, air inlet pipes (25) are arranged on both sides of the air chamber (24), the air inlet pipes (25) are used for inhaling air, two air outlet pipes (26) are arranged on the top of the air chamber (24), the air outlet pipes (26) are used for discharging air, one-way valves are arranged in the air inlet pipes (25) and the air outlet pipes (26), air inlet holes (29) are formed on both sides of the fixed mold (3) and adapted to the air inlet pipes (25), and connecting pipes (45) are arranged on the top of the air outlet pipes (26) and connected to the ejection frame (30).

4. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus according to claim 3, characterized by, The driving assembly includes a positioning plate (12) fixedly installed on one side of the mounting rack (1), a Z-shaped sliding groove (13) is formed in the positioning plate (12), one side of the sliding frame (11) is provided with a vertical rod (14), a connecting seat (15) is slidably installed on the vertical rod (14), one side of the connecting seat (15) is provided with a sliding column (28), the sliding column (28) is slidably installed in the sliding groove (13), when the sliding frame (11) moves away from the fixed mold (3), the connecting seat (15) moves upward under the drive of the sliding column (28), when the sliding frame (11) moves close to the fixed mold (3), the connecting seat (15) moves downward under the drive of the sliding column (28), one side of the connecting seat (15) is provided with a first connecting rod (16), the other side of the first connecting rod (16) is rotatably installed with a second connecting rod (17), the bottom of the fixed mold (3) is slidably installed with a sliding plate (18), one side of the sliding plate (18) is rotatably connected with the second connecting rod (17).

5. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus of claim 4, wherein, The fixed mold (3) is provided with a positioning cavity (32) away from the movable mold (10), the inside of the positioning cavity (32) is fixedly installed with a mounting plate (33), the top of the mounting plate (33) is provided with a sliding groove, the inside of the sliding groove of the mounting plate (33) is slidably installed with a sliding drive plate (34), the sliding drive plate (34) is Z-shaped, the other side of the sliding drive plate (34) is fixedly connected with the ejection frame (30), one side of the mounting plate (33) is also rotatably installed with a rotating rod (36), the bottom of the rotating rod (36) is provided with a second meshing gear (37), one side of the sliding plate (18) is provided with a plurality of second meshing teeth (38) engaged with the second meshing gear (37), the top of the rotating rod (36) is fixedly sleeved with a cam (39), when the rotating rod (36) rotates, the cam (39) is driven to push the sliding drive plate (34) to move, the sliding drive plate (34) synchronously drives the ejection frame (30) to eject outward.

6. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus of claim 5, wherein, One side of the sliding drive plate (34) is provided with a second reset spring (35), the other side of the second reset spring (35) is connected with one side of the inside of the sliding groove.

7. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus of claim 6, wherein, One side of the crank (21) is fixedly sleeved with a first meshing gear (23), the middle top surface of the sliding plate (18) is provided with a plurality of first meshing teeth (19) engaged with the first meshing gear (23).

8. The large thin-walled aluminum alloy cavity vacuum pressure casting apparatus of claim 7, wherein, Both sides of the fixed mold (3) are slidably installed with a second sealing plate (46), the second sealing plate (46) is L-shaped in cross section, and one side of the second sealing plate (46) is fixedly connected with the sliding plate (18), when the movable mold (10) is demolded, the second sealing plate (46) opens the air inlet hole (29).

9. A large thin-walled aluminum alloy cavity vacuum pressure casting use method applied to the large thin-walled aluminum alloy cavity vacuum pressure casting device according to claim 8, characterized in that, The method comprises the following steps: S1: Hydraulic rod (9) drives the slide (11) to retreat, and drives the movable mold (10) to separate from the fixed mold (3); at the same time, the sliding plate (18) moves outwards, the L-shaped sealing plate opens the air inlet hole (29), and the external air starts to enter the air inlet assembly; S2: The sliding plate (18) drives the crank (21) -piston (22) mechanism to move, and forms a negative pressure in the air chamber (24) to suck in cold air, and then compresses the air and pushes it into the hollow ejection frame (30) when moving in the opposite direction; S3: The cam (39) mechanism drives the sliding drive plate (34) to push the ejection frame (30) upwards to eject the casting; the air outlet hole (40) on the surface of the ejection frame (30) is opened under the action of the trigger block (42), and the air flow is sprayed to form an air cushion, which reduces the friction and protects the surface of the mold; S4: During the ejection process, the compressed air flows inside the high-temperature ejection frame (30) and is rapidly heated into hot air, which is temporarily stored in the air outlet module after the ejection is completed; S5: The slide (11) advances, and the crank (21) -piston (22) mechanism acts again to quantitatively spray the heated hot air into the cavity surface, realizing uniform preheating of the mold, and at the same time, the sealing plate closes the air inlet hole (29); S6: The ejection frame (30) and the air outlet hole (40) are reset and tightly sealed under the action of the spring, ensuring the sealing of the cavity; the vacuum adsorber (4) is started to extract the cavity to a high vacuum state, completing the preheating and exhaust closed loop, and preparing for the next casting cycle.

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