Aluminum alloy wheel low pressure casting mold and method of using same

Abstract

The application discloses a low-pressure casting mold for an aluminum alloy wheel hub and a use method thereof and relates to the casting field. The low-pressure casting mold for the aluminum alloy wheel hub comprises a bottom mold, a side mold, a top mold and an ejection mechanism, the side mold is installed at the upper edge of the bottom mold, the top mold is installed directly above the bottom mold and is inserted into the side mold, the bottom mold, the side mold and the top mold jointly form a molding cavity, the ejection mechanism comprises an ejection oil cylinder installed above the top mold and an ejection rod movably inserted into the top mold, a sealing rod is movably inserted into the ejection rod, and a negative pressure pipe is fixedly inserted into the sealing rod. When the top mold rises, the sealing rod moves upwards, the negative pressure pipe is communicated with the molding cavity, and the wheel hub is adsorbed by utilizing negative pressure. During the process that the ejection rod ejects the wheel hub downwards, the negative pressure pipe continuously adsorbs the wheel hub until the adsorption is stopped when the wheel hub is moved to a discharging mechanism.

Description

Technical Field

[0001] This invention relates to the field of casting, and in particular to a low-pressure casting mold for aluminum alloy wheel hubs and its method of use. Background Technology

[0002] In the low-pressure casting production of aluminum alloy wheels, the mold typically includes a bottom mold, side molds, and a top mold. After the wheel hub solidifies within the forming cavity, it needs to be opened and ejected sequentially. The conventional process flow is as follows: first, the side mold is moved to separate it from the wheel hub; then, the top mold is moved upwards, causing it to move the wheel hub to a preset height; finally, the ejector rod ejects the wheel hub from the top mold to the ejection mechanism.

[0003] However, the following problems exist in actual production: First, during the process of the top mold moving upward and driving the wheel hub to rise, the wheel hub may remain stuck in the bottom mold due to the adhesion force with the bottom mold, thus preventing it from rising normally with the top mold; even if the wheel hub successfully detaches from the bottom mold, it may accidentally fall off the top mold during the rising process due to shaking or instability of the center of gravity, causing product damage or safety accidents.

[0004] Secondly, when the top mold rises to the preset height and the ejector rod pushes the hub downwards, the conventional method is to let the hub fall directly onto the discharge mechanism. Due to the height difference, the hub will experience impact and collision when it falls, which may cause dents and scratches on the surface of the hub. Summary of the Invention

[0005] The purpose of this invention is to provide a low-pressure casting mold for aluminum alloy wheel hubs and its method of use, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a low-pressure casting mold for aluminum alloy wheel hubs, comprising: Bottom mold; Side mold, installed on the upper edge of the bottom mold; The top mold is installed directly above the bottom mold and inserted into the side mold. The bottom mold, side mold, and top mold together form a molding cavity. The ejection mechanism includes an ejection cylinder installed above the top mold and an ejection rod movably inserted into the top mold. A sealing rod is movably inserted inside the ejection rod, and a negative pressure pipe is fixedly inserted inside the sealing rod. After the wheel hub is formed, when the top mold moves upward, the sealing rod moves upward relative to the ejector rod, so that the negative pressure pipe is connected to the forming cavity. The negative pressure pipe adsorbs the wheel hub, so that the wheel hub rises steadily with the top mold, avoiding the wheel hub from being left in the bottom mold or falling off the top mold. When the top mold rises to the preset height, the ejector rod extends downwards from the top mold and pushes the hub toward the discharge mechanism. During this ejection process, the negative pressure pipe maintains its adsorption on the hub until the hub is moved onto the discharge mechanism, at which point the negative pressure pipe stops adsorption, and the hub separates from the ejector rod.

[0007] Preferably, a bottom template is fixedly installed at the bottom of the bottom mold, and the bottom template is installed on the worktable of the casting machine; multiple side molds are provided, and a side template is installed on the outer side of each side mold, and the side template is connected to the output end of an external hydraulic cylinder; a top template is fixedly installed at the top of the top mold, and the top template is connected to the output end of an external hydraulic cylinder.

[0008] Preferably, a gate is provided at the center position between the bottom mold and the bottom template, and the gate is connected to the riser pipe of the casting machine.

[0009] Preferably, a support plate is fixedly installed at the bottom of the ejector cylinder, the support plate is fixedly installed on the top template, the output shaft of the ejector cylinder extends downward through the support plate and is fixedly connected to a movable frame, and the movable frame is connected to the top of multiple ejector rods.

[0010] Preferably, multiple sealing cylinders are provided below the movable frame, and the multiple sealing cylinders are arranged one-to-one with multiple ejector rods. The top end of the output shaft of the sealing cylinder extends upward through the movable frame and is fixedly connected to a transmission bar. The top end of the sealing rod extends outward and is fixedly connected to the transmission bar. The top end of the negative pressure pipe extends outward and is connected to the negative pressure air circuit.

[0011] Preferably, an ejector block is fixedly installed at the bottom end of the ejector rod, and a receiving groove is provided on the bottom wall of the top mold, in which the ejector block is embedded.

[0012] Preferably, the bottom of the ejector block has an opening, and the interior of the ejector block has a receiving cavity communicating with the opening. The bottom end of the sealing rod extends into the receiving cavity and is fixedly connected to a sealing block. The bottom end of the sealing block is embedded in the opening, and the lower surface of the sealing block, the lower surface of the ejector block, and the lower surface of the top mold are coplanar.

[0013] Preferably, the sealing block has an air cavity inside, the bottom end of the negative pressure pipe extends to communicate with the air cavity, and the outer wall of the sealing block has a plurality of air holes communicating with the air cavity. During the casting of the wheel hub, the sealing block seals the opening and the receiving cavity; when the wheel hub is demolded, the sealing block moves upward with the sealing rod, causing the bottom end of the sealing block to detach from the opening. At this time, the negative pressure pipe, air cavity, air hole, receiving cavity and opening are connected in sequence to form a negative pressure adsorption channel.

[0014] A method for using a low-pressure casting mold for aluminum alloy wheel hubs, comprising the following steps: S1: Mold closing, where the bottom mold, side mold, and top mold are closed to form a molding cavity, and the wheel hub is cast. S2: After the wheel hub is formed, the top mold moves upward, and at the same time, the sealing rod moves upward relative to the ejector rod, so that the negative pressure pipe is connected to the forming cavity. The negative pressure pipe generates negative pressure to attract the wheel hub, so that the wheel hub rises steadily with the top mold, avoiding the wheel hub from being left in the bottom mold or falling off the top mold. S3: After the top mold rises to the preset height, the ejector rod extends downwards from the top mold, pushing the hub out towards the discharge mechanism. During the ejection process, the negative pressure pipe maintains the adsorption of the hub. S4: When the hub is pushed onto the discharge mechanism, the negative pressure pipe stops adsorption, the hub separates from the push rod, and the discharge is completed.

[0015] Preferably, in step S2, the sealing cylinder drives the transmission bar to move the sealing rod upward, causing the bottom end of the sealing block to detach from the opening, thereby connecting the negative pressure pipe, air chamber, air hole, receiving chamber and opening in sequence to form a negative pressure adsorption channel; in step S4, the sealing cylinder drives the sealing rod downward, causing the sealing block to re-seal the opening, the negative pressure adsorption channel to break, and the hub to separate from the ejector rod.

[0016] The technical effects and advantages of this invention are as follows: This low-pressure casting mold for aluminum alloy wheels utilizes a movable sealing rod and a negative pressure pipe within the ejector rod. As the top mold rises, the sealing rod moves upward, connecting the negative pressure pipe to the forming cavity, thus adsorbing the wheel hub using negative pressure. This adsorption force ensures the wheel hub closely follows the top mold as it rises stably, effectively preventing the wheel hub from sticking to the bottom mold and also preventing it from accidentally falling off the top mold during the ascent, thereby improving the safety and reliability of mold opening.

[0017] This low-pressure casting mold for aluminum alloy wheels features a negative pressure pipe that continuously adheres to the wheel hub as the ejector rod pushes it downwards, continuing to hold the hub in place until it is moved onto the discharge mechanism. This allows the wheel hub to be placed slowly and smoothly onto the discharge mechanism, eliminating direct falls and collisions caused by height differences and preventing damage to the wheel hub surface. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the overall structure of the present invention; Figure 2 This is a structural cross-sectional view of the top mold and ejection mechanism of the present invention; Figure 3 This is a schematic diagram of the top template and ejection mechanism of the present invention; Figure 4 This is a partial structural schematic diagram of the ejection mechanism of the present invention; Figure 5 This is a cross-sectional view of the structure at the connection between the movable frame, the sealing cylinder, and the ejector rod of the present invention. Figure 6 This is a cross-sectional view of the connection between the top mold, the ejector rod, and the ejector block of the present invention. Figure 7 This is a schematic diagram of the method flow of the present invention.

[0019] In the diagram: 1. Bottom mold; 11. Bottom template; 12. Gate; 2. Side mold; 21. Side template; 3. Top mold; 31. Top template; 4. Ejection mechanism; 41. Ejection cylinder; 411. Support plate; 42. Ejection rod; 421. Movable frame; 422. Sealing cylinder; 423. Transmission bar; 43. Sealing rod; 44. Negative pressure pipe; 45. Ejection block; 46. Receiving groove; 451. Receiving cavity; 452. Sealing block; 453. Air cavity; 454. Air hole; 5. Molding cavity. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides, for example Figures 1-6 The low-pressure casting mold for aluminum alloy wheel hubs shown includes: Bottom mold 1; Side mold 2 is installed on the upper edge of bottom mold 1; The top mold 3 is installed directly above the bottom mold 1 and inserted into the side mold 2. The bottom mold 1, the side mold 2 and the top mold 3 together form the molding cavity 5. The ejection mechanism 4 includes an ejection cylinder 41 installed above the top mold 3 and an ejection rod 42 movably inserted into the top mold 3. A sealing rod 43 is movably inserted inside the ejection rod 42, and a negative pressure pipe 44 is fixedly inserted inside the sealing rod 43. After the wheel hub is formed, when the top mold 3 moves upward, the sealing rod 43 moves upward relative to the ejector rod 42, so that the negative pressure pipe 44 is connected to the forming cavity 5. The negative pressure pipe 44 adsorbs the wheel hub, so that the wheel hub rises steadily with the top mold 3, preventing the wheel hub from being left in the bottom mold 1 or falling off the top mold 3. When the top mold 3 rises to the preset height, the ejector rod 42 extends downward from the top mold 3 and ejects the hub toward the discharge mechanism. During this ejection process, the negative pressure pipe 44 maintains its adsorption on the hub until the hub is moved onto the discharge mechanism, at which point the negative pressure pipe 44 stops adsorption and the hub separates from the ejector rod 42.

[0022] Furthermore, a bottom template 11 is fixedly installed at the bottom of the bottom mold 1, and the bottom template 11 is installed on the worktable of the casting machine; multiple side molds 2 are provided, and a side template 21 is installed on the outer side of each side mold 2, and the side template 21 is connected to the output end of the external oil cylinder; a top template 31 is fixedly installed on the top of the top mold 3, and the top template 31 is connected to the output end of the external oil cylinder.

[0023] Furthermore, a gate 12 is provided at the center between the bottom mold 1 and the bottom template 11, and the gate 12 is connected to the riser pipe of the casting machine.

[0024] Furthermore, a support plate 411 is fixedly installed at the bottom of the ejector cylinder 41. The support plate 411 is fixedly installed on the top template 31. The output shaft of the ejector cylinder 41 extends downward through the support plate 411 and is fixedly connected to a movable frame 421. The movable frame 421 is connected to the top of multiple ejector rods 42.

[0025] Furthermore, multiple sealing cylinders 422 are provided below the movable frame 421. The multiple sealing cylinders 422 are provided in a one-to-one correspondence with multiple ejector rods 42. The top end of the output shaft of the sealing cylinder 422 extends upward through the movable frame 421 and is fixedly connected to the transmission bar 423. The top end of the sealing rod 43 extends outward and is fixedly connected to the transmission bar 423. The top end of the negative pressure pipe 44 extends outward and is connected to the negative pressure air passage.

[0026] Furthermore, an ejector block 45 is fixedly installed at the bottom end of the ejector rod 42, and a receiving groove 46 is opened on the bottom wall of the top mold 3, in which the ejector block 45 is embedded.

[0027] Furthermore, the bottom of the ejector block 45 has an opening, and the interior of the ejector block 45 has a receiving cavity 451 that communicates with the opening. The bottom end of the sealing rod 43 extends into the receiving cavity 451 and is fixedly connected to a sealing block 452. The bottom end of the sealing block 452 is embedded in the opening, and the lower surface of the sealing block 452, the lower surface of the ejector block 45, and the lower surface of the top mold 3 are coplanar.

[0028] Furthermore, the sealing block 452 has an air cavity 453 inside, the bottom end of the negative pressure pipe 44 extends to communicate with the air cavity 453, and the outer wall of the sealing block 452 has a plurality of air holes 454 communicating with the air cavity 453. During the casting of the wheel hub, the sealing block 452 seals the opening and the receiving cavity 451; when the wheel hub is demolded, the sealing block 452 moves upward with the sealing rod 43, causing the bottom end of the sealing block 452 to detach from the opening. At this time, the negative pressure pipe 44, the air cavity 453, the air hole 454, the receiving cavity 451 and the opening are connected in sequence to form a negative pressure adsorption channel.

[0029] By incorporating a movable sealing rod 43 and a negative pressure pipe 44 within the ejector rod 42, the sealing rod 43 moves upward as the top mold 3 rises, connecting the negative pressure pipe 44 to the molding cavity 5, thus utilizing negative pressure to adsorb the wheel hub. This adsorption force ensures that the wheel hub closely follows the top mold 3 as it rises stably, effectively preventing the wheel hub from sticking to the bottom mold 1 and also preventing the wheel hub from accidentally falling off the top mold 3 during the rising process, thereby improving the safety and reliability of mold opening.

[0030] As the ejector rod 42 pushes the hub downwards, the negative pressure pipe 44 continuously maintains its adsorption on the hub until the hub is moved onto the discharge mechanism. This allows the hub to be placed slowly and smoothly on the discharge mechanism, eliminating direct falls and collisions caused by height differences and preventing damage to the hub surface.

[0031] like Figure 7 The method of using a low-pressure casting mold for aluminum alloy wheel hubs, as shown, involves the following steps: S1: Mold closing, so that the bottom mold 1, side mold 2 and top mold 3 are closed to form the molding cavity 5, and the wheel hub is cast. S2: After the wheel hub is formed, the top mold 3 moves upward, and at the same time, the sealing rod 43 is controlled to move upward relative to the ejector rod 42, so that the negative pressure pipe 44 is connected to the forming cavity 5. The negative pressure pipe 44 generates negative pressure to attract the wheel hub, so that the wheel hub rises steadily with the top mold 3, and avoids the wheel hub from being left in the bottom mold 1 or falling off the top mold 3. S3: After the top mold 3 rises to the preset height, the ejector rod 42 extends downward from the top mold 3, pushing the hub out towards the discharge mechanism. During the ejection process, the negative pressure pipe 44 maintains the adsorption of the hub. S4: When the hub is pushed onto the discharge mechanism, the negative pressure pipe 44 stops adsorption, the hub separates from the push rod 42, and the discharge is completed.

[0032] Furthermore, in step S2, the sealing cylinder 422 drives the transmission bar 423 to move the sealing rod 43 upward, causing the bottom end of the sealing block 452 to detach from the opening, thereby connecting the negative pressure pipe 44, the air chamber 453, the air hole 454, the receiving cavity 451 and the opening in sequence to form a negative pressure adsorption channel; in step S4, the sealing cylinder 422 drives the sealing rod 43 downward, causing the sealing block 452 to re-seal the opening, the negative pressure adsorption channel is disconnected, and the hub separates from the ejector rod 42.

[0033] A bottom template 11 is fixedly installed at the bottom of the bottom mold 1, and the bottom template 11 is fixedly installed on the worktable of the casting machine. A gate 12 is set at the center between the bottom mold 1 and the bottom template 11. The gate 12 is connected to the riser pipe of the casting machine and is used to inject molten aluminum alloy into the forming cavity 5. Side molds 2 are installed on the upper edge of the bottom mold 1. Multiple side molds 2 are provided, and a side template 21 is installed on the outer side of each side mold 2. The side template 21 is connected to the output end of an external hydraulic cylinder. When the mold is closed, the external hydraulic cylinder pushes the side mold 2 to move towards the center; when the mold is opened, the external hydraulic cylinder pulls the side mold 2 to move outward, so that the side mold 2 separates from the hub. The top mold 3 is installed directly above the bottom mold 1 and inserted into the side molds 2. A top template 31 is fixedly installed on the top of the top mold 3. The top template 31 is connected to the output end of an external hydraulic cylinder and is used to drive the top mold 3 to move up and down. The bottom mold 1, side mold 2 and top mold 3 are combined to form a molding cavity 5, and the wheel hub is solidified and formed by low-pressure casting in the molding cavity 5.

[0034] The ejection mechanism 4 includes an ejection cylinder 41, ejection rods 42, a sealing rod 43, and a negative pressure pipe 44. The ejection cylinder 41 is installed above the top mold 3. Specifically, a support plate 411 is fixedly installed at the bottom of the ejection cylinder 41, and the support plate 411 is fixedly installed on the top mold plate 31. The output shaft of the ejection cylinder 41 extends downward through the support plate 411 and is fixedly connected to a movable frame 421. The movable frame 421 is connected to the top ends of multiple ejection rods 42. The ejection rods 42 are movably inserted into the top mold 3 and can move up and down relative to the top mold 3.

[0035] The ejector rod 42 is hollow inside, and a sealing rod 43 is movably inserted into it. The sealing rod 43 is also hollow inside, and a negative pressure pipe 44 is fixedly inserted into it. The top end of the negative pressure pipe 44 extends outward and connects to an external negative pressure air path, such as a vacuum pump or a factory negative pressure system. Specifically, multiple sealing cylinders 422 are arranged below the movable frame 421, and each sealing cylinder 422 corresponds to one of the ejector rods 42. The top end of the output shaft of the sealing cylinder 422 extends upward through the movable frame 421 and is fixedly connected to a transmission bar 423. The top end of the sealing rod 43 extends outward and is fixedly connected to the other end of the transmission bar 423. In this way, the sealing cylinder 422 can independently drive the sealing rod 43 to move up and down relative to the ejector rod 42.

[0036] An ejector block 45 is fixedly installed at the bottom end of the ejector rod 42. A receiving groove 46 is formed in the bottom wall of the top mold 3, and the ejector block 45 is embedded in the receiving groove 46, making the lower surface of the top mold 3 flat. An opening is formed at the bottom of the ejector block 45, and a receiving cavity 451 communicating with the opening is formed inside the ejector block 45. The bottom end of the sealing rod 43 extends into the receiving cavity 451 and is fixedly connected to a sealing block 452. In the non-adsorption state, i.e., during the casting and pressure holding stages, the bottom end of the sealing block 452 is embedded in the opening, and the lower surface of the sealing block 452, the lower surface of the ejector block 45, and the lower surface of the top mold 3 are coplanar, thereby ensuring the surface quality of the molded cavity 5.

[0037] The sealing block 452 has an internal air chamber 453, and the bottom end of the negative pressure pipe 44 extends to communicate with the air chamber 453. The outer wall of the sealing block 452 has multiple air holes 454 communicating with the air chamber 453. During the wheel hub casting process, the sealing block 452 closes the opening and the receiving cavity 451, and the negative pressure channel is disconnected to prevent molten aluminum from entering.

[0038] The work process is as follows: Step S1: The external hydraulic cylinder drives the top mold 3 to close downwards and drives the side mold 2 to move towards the center, so that the bottom mold 1, side mold 2, and top mold 3 form a sealed molding cavity 5. Molten aluminum alloy is injected into the molding cavity 5 through the riser pipe and the gate 12, and the wheel hub is solidified by pressure holding and cooling. At this time, the sealing cylinder 422 is in the retracted state, the sealing block 452 blocks the opening, and the negative pressure pipe 44 is not connected to the molding cavity 5.

[0039] Step S2: After the wheel hub is formed, the external hydraulic cylinder first drives the side mold 2 to move outward, separating the side mold 2 from the wheel hub. Then, the external hydraulic cylinder drives the top mold plate 31 to move the top mold 3 upward. At the same time, the sealing hydraulic cylinder 422 is activated, and its output shaft extends upward, driving the sealing rod 43 to move upward relative to the ejector rod 42 through the transmission bar 423. The sealing rod 43 drives the sealing block 452 to move upward, causing the bottom end of the sealing block 452 to disengage from the opening. At this time, the negative pressure pipe 44, air chamber 453, air hole 454, receiving cavity 451 and opening are connected in sequence to form a negative pressure adsorption channel. The external negative pressure air passage is connected, and negative pressure is generated in the negative pressure pipe 44, which adsorbs onto the upper surface of the wheel hub through the opening. This adsorption force makes the wheel hub closely follow the top mold 3 and rise steadily. Even if there is an adhesive force between the wheel hub and the bottom mold 1, it can overcome this force and detach from the bottom mold 1; at the same time, the adsorption force always exists during the rising process, preventing the wheel hub from falling off the top mold 3 due to shaking or center of gravity shift.

[0040] Step S3: When the top mold 3 rises to a preset height, typically a sufficient safe distance above the discharge mechanism, the discharge mechanism (not shown in the figure) moves below the top mold 3. The ejector cylinder 41 is activated, its output shaft extends downwards, pushing the movable frame 421 and the ejector rod 42 downwards as a whole. The ejector block 45 at the bottom of the ejector rod 42 extends from the receiving groove 46, pushing the hub towards the downward discharge mechanism. During this ejection process, the sealing cylinder 422 remains extended, and the negative pressure pipe 44 continuously generates negative pressure, maintaining the attraction to the hub. Therefore, when the hub is pushed downwards by the ejector rod 42, it will not fall directly due to gravity, but will be attracted and slowly descend until it approaches or contacts the discharge mechanism.

[0041] Step S4: When the hub is moved onto the discharge mechanism, i.e., when the lower surface of the hub is in contact with or very close to the discharge mechanism, the negative pressure air path is cut off. At the same time, the sealing cylinder 422 retracts, driving the sealing rod 43 to move downward, causing the sealing block 452 to re-seal the opening, the negative pressure adsorption channel is disconnected, and the hub separates from the ejector rod 42. Subsequently, the ejector cylinder 41 drives the ejector rod 42 to reset upward, the top mold 3 and other components reset, completing a complete casting and discharge cycle.

[0042] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-pressure casting mold for aluminum alloy wheel hubs, characterized in that, include: Bottom mold (1); Side mold (2) is installed on the upper edge of bottom mold (1); The top mold (3) is installed directly above the bottom mold (1) and inserted into the side mold (2). The bottom mold (1), the side mold (2) and the top mold (3) together form a molding cavity (5). The ejection mechanism (4) includes an ejection cylinder (41) installed above the top mold (3) and an ejection rod (42) movably inserted into the top mold (3). A sealing rod (43) is movably inserted inside the ejection rod (42), and a negative pressure pipe (44) is fixedly inserted inside the sealing rod (43). After the wheel hub is formed, when the top mold (3) moves upward, the sealing rod (43) moves upward relative to the ejector rod (42), so that the negative pressure pipe (44) is connected to the forming cavity (5), and the negative pressure pipe (44) adsorbs the wheel hub, so that the wheel hub rises steadily with the top mold (3); When the top mold (3) rises to the preset height, the ejector rod (42) extends downward from the top mold (3) and ejects the hub toward the discharge mechanism. During this ejection process, the negative pressure pipe (44) maintains its adsorption on the hub until the hub is moved onto the discharge mechanism, at which point the negative pressure pipe (44) stops adsorption and the hub separates from the ejector rod (42).

2. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 1, characterized in that, The bottom mold (1) is fixedly installed with a bottom template (11), which is installed on the worktable of the casting machine; multiple side molds (2) are provided, and a side template (21) is installed on the outside of each side mold (2), which is connected to the output end of the external oil cylinder; the top mold (3) is fixedly installed with a top template (31), which is connected to the output end of the external oil cylinder.

3. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 2, characterized in that, A gate (12) is provided at the center between the bottom mold (1) and the bottom template (11), and the gate (12) is connected to the riser pipe of the casting machine.

4. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 2, characterized in that, The bottom of the ejector cylinder (41) is fixedly installed with a support plate (411), which is fixedly installed on the top template (31). The output shaft of the ejector cylinder (41) extends downward through the support plate (411) and is fixedly connected to a movable frame (421). The movable frame (421) is connected to the top of multiple ejector rods (42).

5. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 4, characterized in that, Multiple sealing cylinders (422) are provided below the movable frame (421). The multiple sealing cylinders (422) are provided one-to-one with multiple ejector rods (42). The top end of the output shaft of the sealing cylinder (422) extends upward through the movable frame (421) and is fixedly connected to the transmission bar (423). The top end of the sealing rod (43) extends outward and is fixedly connected to the transmission bar (423). The top end of the negative pressure pipe (44) extends outward and is connected to the negative pressure air passage.

6. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 1, characterized in that, An ejector block (45) is fixedly installed at the bottom end of the ejector rod (42), and a receiving groove (46) is opened on the bottom wall of the top mold (3), and the ejector block (45) is embedded in the receiving groove (46).

7. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 6, characterized in that, The bottom of the ejector block (45) has an opening, and the interior of the ejector block (45) has a receiving cavity (451) communicating with the opening. The bottom end of the sealing rod (43) extends into the receiving cavity (451) and is fixedly connected to a sealing block (452). The bottom end of the sealing block (452) is embedded in the opening, and the lower surface of the sealing block (452), the lower surface of the ejector block (45), and the lower surface of the top mold (3) are coplanar.

8. The low-pressure casting mold for aluminum alloy wheel hubs according to claim 7, characterized in that, The sealing block (452) has an air cavity (453) inside, the bottom end of the negative pressure pipe (44) extends to communicate with the air cavity (453), and the outer wall of the sealing block (452) has a plurality of air holes (454) communicating with the air cavity (453). During the casting of the wheel hub, the sealing block (452) closes the opening and the receiving cavity (451); when the wheel hub is demolded, the sealing block (452) moves upward with the sealing rod (43), so that the bottom end of the sealing block (452) is separated from the opening. At this time, the negative pressure pipe (44), the air cavity (453), the air hole (454), the receiving cavity (451) and the opening are connected in sequence to form a negative pressure adsorption channel.

9. A method of using a low-pressure casting mold for aluminum alloy wheel hubs, employing the casting mold described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Close the mold, so that the bottom mold (1), side mold (2) and top mold (3) are closed to form a molding cavity (5), and cast the molded wheel hub; S2: After the wheel hub is formed, the top mold (3) moves upward, and at the same time, the sealing rod (43) is controlled to move upward relative to the ejector rod (42), so that the negative pressure pipe (44) is connected to the forming cavity (5). The negative pressure pipe (44) generates negative pressure to attract the wheel hub, so that the wheel hub rises steadily with the top mold (3) to avoid the wheel hub being left in the bottom mold (1) or falling off the top mold (3). S3: After the top mold (3) rises to the preset height, the ejector rod (42) extends downward from the top mold (3) and ejects the hub toward the discharge mechanism. During the ejection process, the negative pressure pipe (44) maintains the adsorption of the hub. S4: When the hub is pushed onto the discharge mechanism, the negative pressure pipe (44) stops adsorption, the hub separates from the push rod (42), and the discharge is completed.

10. The method of using a low-pressure casting mold for aluminum alloy wheel hubs according to claim 9, characterized in that, In step S2, the sealing cylinder (422) drives the transmission bar (423) to move the sealing rod (43) upward, so that the bottom end of the sealing block (452) is separated from the opening, thereby connecting the negative pressure pipe (44), the air chamber (453), the air hole (454), the receiving cavity (451) and the opening in sequence to form a negative pressure adsorption channel; in step S4, the sealing cylinder (422) drives the sealing rod (43) downward, so that the sealing block (452) re-seals the opening, the negative pressure adsorption channel is disconnected, and the hub is separated from the ejector rod (42).

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