Method and device for gravity casting of an aluminum piece

Abstract

This invention relates to the field of gravity casting technology, specifically to a method and apparatus for gravity casting of aluminum parts. The method includes step two: pouring molten aluminum into a casting pipe, with a one-way baffle inside the casting pipe remaining closed, allowing the molten aluminum to be stored in a reservoir section upstream of the one-way baffle; step three: driving a rotating mechanism to tilt the fixed mold, moving mold, and casting pipe from a horizontal to a vertical position. During the tilting process, the molten aluminum stored in the reservoir section exerts a pushing force on the one-way baffle, causing the one-way baffle to open towards the forming chamber under the action of the molten aluminum's pushing force and its own gravity, allowing the molten aluminum to flow into the forming chamber. This method divides the casting process into two stages: horizontal reservoir and tilting injection, achieving the effect of allowing the molten aluminum to overcome resistance, push open the one-way baffle, and smoothly inject along the lower sidewall of the cavity in a laminar flow manner during tilting.

Description

Technical Field

[0001] This invention relates to the field of gravity casting technology, and more specifically, to a method and apparatus for gravity casting of aluminum parts. Background Technology

[0002] In the gravity casting process of aluminum parts, a casting device with a tilting mechanism is commonly used. The working principle of this device is as follows: first, the fixed mold and the moving mold are closed and rotated together with the pouring pipe to a horizontal state. Then, the high-temperature aluminum liquid is poured directly into the pouring pipe. After the pouring is completed, the mold and the pouring pipe are rotated to a vertical state by the rotating mechanism, so that the aluminum liquid solidifies and forms under the action of gravity.

[0003] However, the existing process of first pouring horizontally and then tilting has certain limitations. When the equipment is horizontal and molten aluminum is poured in, the molten aluminum enters from the gate and flows directly into the mold cavity through the horizontal pipe. During this process, because the mold cavity is originally filled with air, and the top plane of the cavity faces upward in the horizontal position, the gas is difficult to expel and tends to stagnate at high points or dead corners of the cavity. During the rapid filling of the molten aluminum, these stagnant gases are easily entrained and trapped by the molten aluminum, forming bubbles.

[0004] As the mold tilts from a horizontal to a vertical position, while this facilitates feeding and venting during solidification, it makes it difficult to effectively remove air bubbles already trapped inside the molten aluminum. Ultimately, these bubbles will form pores inside the casting or react with the molten aluminum to form oxide inclusions, significantly reducing the density and mechanical properties of the casting and affecting the product yield. Summary of the Invention

[0005] This invention provides a method and apparatus for gravity casting of aluminum parts, which achieves the effect of storing aluminum liquid first and then tilting and filling it by setting a one-way baffle in the injection pipe, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a gravity casting method for aluminum parts, comprising the following steps: Step 1: Closing the fixed mold and the moving mold, the internal cavities of which together constitute the forming chamber. The injection pipes on the fixed mold and the moving mold are connected to the forming chamber, and the fixed mold, the moving mold, and the injection pipes are kept horizontal by a rotating mechanism; Step 2: Pouring molten aluminum into the injection pipe, with the one-way baffle inside the injection pipe kept closed, so that the molten aluminum is stored in the liquid storage section upstream of the one-way baffle; Step 3: Driving the rotating mechanism... The fixed mold, moving mold, and gating pipe tilt from a horizontal to a vertical position. During the tilting process, the molten aluminum stored in the liquid storage section exerts a pushing force on the one-way baffle. Under the action of the pushing force of the molten aluminum and its own gravity, the one-way baffle opens towards the forming chamber, allowing the molten aluminum to flow into the forming chamber. Step 4: The molten aluminum entering the forming chamber fills and solidifies under the action of gravity. Step 5: After the aluminum part is formed, the fixed mold, moving mold, and gating pipe are rotated back to a horizontal position by a rotating mechanism. Finally, the fixed mold and moving mold are separated, and the formed aluminum part is taken out.

[0007] The present invention also provides an aluminum part gravity casting molding device, including a base, a fixed mold, a movable mold, and a rotating mechanism. After the fixed mold and the movable mold are closed, they form a molding chamber for forming aluminum parts. The outer walls of the fixed mold and the movable mold are provided with injection pipes that communicate with the molding chamber. The rotating mechanism is provided on the base and is used to drive the fixed mold, the movable mold, and the injection pipes to tilt between a horizontal state and a vertical state. A one-way baffle is provided inside the injection pipe, which divides the injection pipe into a liquid storage section located upstream of the one-way baffle and a liquid inlet section located downstream of the one-way baffle.

[0008] In the above technical solution, when the injection pipe is in a horizontal state, the one-way baffle remains closed so that the molten aluminum poured from the inlet end of the injection pipe is stored in the liquid storage section. During the process of the injection pipe tilting from a horizontal state to a vertical state, the one-way baffle opens in one direction toward the forming chamber under the thrust of the molten aluminum and its own gravity, so that the molten aluminum stored in the liquid storage section flows into the forming chamber through the liquid inlet section.

[0009] Based on the above, the injection pipe includes a first half-pipe fixedly installed on the outer wall of the fixed mold, a second half-pipe fixedly installed on the outer wall of the moving mold, a liquid pouring cylinder fixedly installed on the top surface of the second half-pipe, and a liquid storage box fixedly installed on the bottom surface of the first half-pipe for storing liquid. When the fixed mold and the moving mold are closed, the first half-pipe and the second half-pipe are also closed and together form the injection pipe.

[0010] A one-way baffle is hinged to the inner wall of the first half-tube.

[0011] The fixed mold has a channel for liquid inlet on the side near the first half-tube, which communicates with the molding chamber, and the moving mold has an exhaust hole for exhaust on the side near the second half-tube, which communicates with the channel.

[0012] The inner wall of the second half-tube is fixedly equipped with an exhaust pipe that communicates with the exhaust port, so as to discharge the gas in the forming chamber when the aluminum liquid flows into the forming chamber.

[0013] The exhaust pipe includes an inclined section, a reaction section, and a discharge section. The reaction section is equipped with two symmetrically arranged shape memory metal springs to adjust the size of the internal air passage of the exhaust pipe according to the temperature of the exhaust gas.

[0014] The inner wall of the first half-tube is provided with an installation groove, the inside of which is equipped with a limit ball, and the inner wall of the installation groove is also equipped with a return spring.

[0015] An arc-shaped plate is fixedly installed on the outer wall of the one-way baffle, and a groove is opened on the bottom surface of the exhaust pipe to limit the one-way rotation of the arc-shaped plate, and the inner wall of the groove is in rotational contact with the outer wall of the one-way baffle.

[0016] The rotating mechanism includes a support base fixedly mounted on the base, a rotating frame rotatably mounted on the support base, a first fixed plate fixedly mounted on the outer wall of the rotating frame, a second fixed plate fixedly mounted on the outer wall of the rotating frame, a movable plate movably disposed between the first fixed plate and the second fixed plate, a second telescopic rod fixedly mounted on the first fixed plate, and a first telescopic rod hinged to the base. The movable end of the second telescopic rod is fixedly connected to the outer wall of the movable plate, and the movable end of the first telescopic rod is rotatably connected to the outer wall of the rotating frame. The movable mold is fixedly mounted on the side of the movable plate near the second fixed plate, and the fixed mold is fixedly mounted on the side of the second fixed plate near the first fixed plate.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. In this gravity casting method and apparatus for aluminum parts, by setting a one-way baffle in the pouring pipe, the pouring process is divided into two stages: horizontal liquid storage and tilting liquid pouring. This achieves the effect that during tilting, the molten aluminum overcomes resistance, pushes aside the one-way baffle, and is smoothly poured into the mold cavity in a laminar flow manner along the lower sidewall. This solves the problem of air being easily entangled in the molten aluminum due to impact on the mold cavity during horizontal direct pouring, reduces defects such as porosity and oxide inclusions, and improves the mechanical properties of the aluminum parts.

[0019] 2. In this gravity casting method and apparatus for aluminum parts, by setting vent holes and vent pipes with matching liquid inlet channels on the fixed mold and the moving mold, and by setting a heat-deformable shape memory metal spring in the vent pipe, the ventilation cross-section is automatically adjusted during aluminum liquid filling to smoothly discharge gas from the cavity, and the entry of external impurities is reduced during non-casting states. This achieves orderly gas discharge, reduces dead corners in the cavity and gas stagnation at the top, and further improves the density and molding quality of the casting. Attached Figure Description

[0020] Figure 1A schematic diagram showing the closed state of the fixed mold and moving mold in the gravity casting forming device for aluminum parts;

[0021] Figure 2 This is a schematic diagram showing the state of the first and second halves of the aluminum part when they separate in a gravity casting device.

[0022] Figure 3 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the middle;

[0023] Figure 4 This is a schematic diagram of the installation of the exhaust pipe in a gravity casting device for aluminum parts.

[0024] Figure 5 A schematic diagram of the channel and vent in a gravity casting device for aluminum parts;

[0025] Figure 6 For the present invention Figure 5 Enlarged schematic diagram of the structure at point B;

[0026] Figure 7 This is a schematic diagram of the installation of the limiting ball in the gravity casting forming device for aluminum parts;

[0027] Figure 8 A schematic diagram of the installation of shape memory metal springs in a gravity casting device for aluminum parts;

[0028] Figure 9 This is a schematic diagram of a one-way baffle in a gravity casting device for aluminum parts in a tilted state.

[0029] Figure 10 This is a schematic diagram of a unidirectional baffle in a gravity casting device for aluminum parts in a vertical position.

[0030] The meanings of the labels in the diagram are as follows:

[0031] 100. Base; 101. Support base; 102. Rotating frame; 103. First telescopic rod; 104. First fixed plate; 105. Second fixed plate; 106. Fixed mold; 107. Movable plate; 108. Moving mold; 109. Second telescopic rod;

[0032] 200. Channel; 201. First half-pipe; 202. Second half-pipe; 203. Liquid pouring cylinder; 204. Liquid storage box; 205. Vent hole; 206. Vent pipe;

[0033] 300. One-way baffle; 301. Mounting groove; 302. Limit ball; 303. Return spring; 304. Arc-shaped plate; 305. Groove;

[0034] 400. Inclined section; 401. Reaction section; 402. Outgoing section; 403. Memory metal fragment. Detailed Implementation

[0035] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0036] Example 1, Reference Figures 1-2 ,as well as Figures 9-10 As shown, the present invention illustrates a gravity casting method for aluminum parts, including the following steps: Step 1: Close the fixed mold 106 and the moving mold 108, the internal cavities of the two together form a forming chamber, the injection pipes on the fixed mold 106 and the moving mold 108 are connected to the forming chamber, and the fixed mold 106, the moving mold 108 and the injection pipes are kept in a horizontal state by a rotating mechanism.

[0037] It should be noted that when the fixed mold 106 and the moving mold 108 are closed, the fixed mold 106 and the moving mold 108 move closer to each other, so that the edges of the cavities inside them correspond and fit together to form a relatively closed molding chamber. At the same time, the injection pipes provided on the fixed mold 106 and the moving mold 108 are also closed, so that a continuous passage for the flow of molten aluminum is formed between the injection pipes and the molding chamber.

[0038] The rotating mechanism enables the fixed mold 106, the moving mold 108, and the pouring pipe to rotate synchronously, preventing changes in their relative positions during tilting. Before pouring in molten aluminum, the fixed mold 106, the moving mold 108, and the pouring pipe are kept horizontal, facilitating the pouring of molten aluminum from the inlet end of the pouring pipe and temporarily storing the poured aluminum within it. Furthermore, after the fixed mold 106 and the moving mold 108 close, their closed state can be maintained to prevent separation between them during subsequent tilting and filling processes, thereby reducing the possibility of molten aluminum leaking from their joint.

[0039] Step 2: Pour the molten aluminum into the pouring pipe. With the one-way baffle 300 inside the pouring pipe closed, the molten aluminum is stored in the liquid storage section upstream of the one-way baffle 300.

[0040] The one-way baffle 300 divides the casting pipe into a liquid storage section on the upstream side and a liquid inlet section on the downstream side. The liquid storage section is located near the inlet end of the casting pipe, and the liquid inlet section is located near the molding chamber. When the one-way baffle 300 is in the closed state, it blocks the flow of molten aluminum between the liquid storage section and the liquid inlet section, preventing the molten aluminum from immediately rushing into the molding chamber after being poured into the casting pipe.

[0041] It should be noted that the temporary accumulation of molten aluminum in the storage section transforms the traditional direct pouring process into a process of first storing the molten aluminum and then pouring it in a tilting manner. By temporarily blocking the molten aluminum with a one-way baffle 300, the direct impact of the molten aluminum on the inner wall of the forming cavity when the mold is in a horizontal state can be reduced, and conditions can be provided for the smooth pouring of the molten aluminum in the subsequent tilting state.

[0042] When molten aluminum is poured in, it enters the storage section from the inlet end of the pouring pipe, where it is received and stored. Because the one-way baffle 300 remains closed, the air already inside the forming cavity is not subjected to rapid compression caused by the sudden entry of molten aluminum, which helps reduce violent mixing of molten aluminum and air, as well as air entrapment.

[0043] Step 3: Drive the fixed mold 106, the moving mold 108 and the injection pipe to tilt from the horizontal state to the vertical state through the rotation mechanism. During the tilting process, the aluminum liquid stored in the liquid storage section exerts a pushing force on the one-way baffle 300. Under the action of the aluminum liquid pushing force and its own gravity, the one-way baffle 300 opens towards the forming chamber so that the aluminum liquid flows into the forming chamber.

[0044] As the fixed mold 106, the moving mold 108, and the injection pipe gradually tilt, the direction of gravity acting on the molten aluminum in the storage section changes relative to the injection pipe, causing the molten aluminum to gradually gather at the location of the one-way baffle 300 and generate a thrust on the one-way baffle 300 toward the molding chamber.

[0045] The one-way baffle 300 can only open in the direction of the forming chamber and cannot rotate in the opposite direction to the liquid storage section. When the thrust generated by the molten aluminum on the one-way baffle 300 and the opening effect formed by the weight of the one-way baffle 300 itself reach a level that can overcome its closing limiting effect, the one-way baffle 300 is pushed open, and the liquid storage section and the liquid inlet section are connected.

[0046] It should be noted that the horizontal and vertical states described in this embodiment are mainly used to describe the relative postures of the fixed mold 106, the moving mold 108, and the pouring pipe during the casting process. It is not required that each component must be absolutely horizontal or absolutely vertical, as long as it can achieve temporary storage of molten aluminum and gravity filling after tilting.

[0047] Step 4: The molten aluminum entering the molding chamber fills and solidifies under the action of gravity.

[0048] In this process, after the molten aluminum enters the forming chamber, it gradually fills all areas of the chamber under its own gravity. As the level of the molten aluminum rises, the air inside the forming chamber is gradually squeezed out, allowing the molten aluminum to fill the forming chamber more completely.

[0049] Once the fixed mold 106, the moving mold 108, and the injection pipe are rotated to a vertical position, their current positions can be maintained by the rotation mechanism, allowing the molten aluminum in the forming cavity to solidify in a relatively stable state. During solidification, the fixed mold 106 and the moving mold 108 together define the shape of the aluminum part and support the molten aluminum.

[0050] Step 5: After the aluminum part is formed, the fixed mold 106, the moving mold 108 and the injection pipe are rotated back to the horizontal state by the rotating mechanism. Finally, the fixed mold 106 and the moving mold 108 are separated and the formed aluminum part is taken out.

[0051] After confirming that the molten aluminum in the molding chamber has solidified and formed an aluminum part, the rotating mechanism drives the fixed mold 106, the moving mold 108 and the injection pipe to rotate in the opposite direction, so that the three are restored from the vertical state to the horizontal state, so as to carry out the mold opening and part removal operations.

[0052] Furthermore, after the fixed mold 106 and the moving mold 108 return to a horizontal position, the moving mold 108 is moved away from the fixed mold 106 to open the forming chamber and expose the formed aluminum part. Subsequently, the formed aluminum part can be removed from between the fixed mold 106 and the moving mold 108, and the fixed mold 106, the moving mold 108, and the gating pipes can be cleaned to prepare for the next casting operation.

[0053] In addition, after the molten aluminum is discharged and the device returns to a horizontal position, the one-way baffle 300 can return to the closed position under its own gravity so that the molten aluminum can continue to be temporarily stored when the molten aluminum is poured in again.

[0054] Example 2, refer to Figures 1-3 This invention discloses a gravity casting molding device for aluminum parts, including a base 100, a fixed mold 106, a movable mold 108, and a rotating mechanism. After the fixed mold 106 and the movable mold 108 are closed, they form a molding chamber for forming aluminum parts. The outer walls of the fixed mold 106 and the movable mold 108 are provided with injection pipes that communicate with the molding chamber. The rotating mechanism is provided on the base 100 and is used to drive the fixed mold 106, the movable mold 108, and the injection pipes to tilt between a horizontal state and a vertical state. A one-way baffle 300 is provided inside the injection pipe, which divides the injection pipe into a liquid storage section located upstream of the one-way baffle 300 and a liquid inlet section located downstream of the one-way baffle 300.

[0055] It should be noted that after the fixed mold 106 and the moving mold 108 are closed, the corresponding cavities inside them together form a forming chamber, and the shape of the forming chamber corresponds to the shape of the aluminum part to be formed.

[0056] When the casting pipe is in a horizontal state, the one-way baffle 300 remains closed so that the molten aluminum poured from the inlet end of the casting pipe is stored in the storage section; during the process of the casting pipe tilting from a horizontal state to a vertical state, the one-way baffle 300 opens in one direction toward the forming chamber under the thrust exerted by the molten aluminum and its own gravity, so that the molten aluminum stored in the storage section flows into the forming chamber through the inlet section.

[0057] Furthermore, by utilizing the unidirectional baffle 300 to form a pre-storage, post-injection structure, the molten aluminum enters the forming chamber during mold tilting, reducing the direct impact of the molten aluminum on the forming chamber in the horizontal direction. The molten aluminum can gradually flow along the relatively low inner wall of the forming chamber, allowing air in the forming chamber to be gradually expelled as the molten aluminum level rises.

[0058] Combination Figure 5 As shown, the injection pipe includes a first half-pipe 201 fixedly installed on the outer wall of the fixed mold 106, a second half-pipe 202 fixedly installed on the outer wall of the moving mold 108, a liquid pouring cylinder 203 fixedly installed on the top surface of the second half-pipe 202, and a liquid storage box 204 fixedly installed on the bottom surface of the first half-pipe 201 for storing liquid. When the fixed mold 106 and the moving mold 108 are closed, the first half-pipe 201 and the second half-pipe 202 are also closed and together form the injection pipe.

[0059] The first half-tube 201 can move synchronously with the fixed mold 106, and the second half-tube 202 can move synchronously with the moving mold 108. When the fixed mold 106 and the moving mold 108 are closed, the first half-tube 201 and the second half-tube 202 are fitted together, so that their internal spaces are interconnected and form a complete injection pipe; when the fixed mold 106 and the moving mold 108 are separated, the first half-tube 201 and the second half-tube 202 are also separated, which facilitates the cleaning of residual aluminum material inside the injection pipe.

[0060] Specifically, the pouring cylinder 203 forms an inlet for pouring molten aluminum, which can receive and guide the poured molten aluminum, reducing the possibility of molten aluminum falling outside the pouring pipe. When the pouring pipe is in a horizontal state and the one-way baffle 300 remains closed, the storage box 204 and the corresponding area of ​​the first half-pipe 201 together form a storage space for containing molten aluminum, so that the molten aluminum entering from the pouring cylinder 203 can temporarily accumulate on the upstream side of the one-way baffle 300.

[0061] Depend on Figure 6 As shown, the one-way baffle 300 is hinged to the inner wall of the first half-tube 201.

[0062] Specifically, the hinge structure between the one-way baffle 300 and the first half-tube 201 allows the one-way baffle 300 to rotate relative to the first half-tube 201. When the one-way baffle 300 is closed, it blocks the pouring channel formed by the first half-tube 201 and the second half-tube 202. When the one-way baffle 300 is open, it forms an opening in the pouring channel for the passage of molten aluminum.

[0063] The movable end of the one-way baffle 300 is positioned towards the direction of the forming chamber, allowing the one-way baffle 300 to rotate toward the forming chamber under the thrust of the molten aluminum, while being restricted when subjected to a force in the opposite direction, thus forming a one-way check valve structure.

[0064] Combined again Figure 5 As shown, the fixed mold 106 has a channel 200 for liquid inlet on the side near the first half-tube 201, which communicates with the molding chamber, and the moving mold 108 has an exhaust hole 205 for exhaust on the side near the second half-tube 202, which communicates with the channel 200.

[0065] One end of channel 200 is connected to the inlet section of the casting pipe, and the other end is connected to the forming chamber. After the one-way baffle 300 is opened, the molten aluminum enters the inlet section from the storage section and flows into the forming chamber through channel 200. Specifically, the vent 205 is connected to channel 200. As the molten aluminum gradually fills the forming chamber, the air originally in the forming chamber can enter the vent 205 under the pressure of the molten aluminum, thereby reducing the situation where air is trapped in the high area or dead corners of the forming chamber.

[0066] Furthermore, the channel 200 and the vent 205 respectively serve the functions of liquid inlet and vent outlet, ensuring that the inflow path of the molten aluminum and the outflow path of the gas are coordinated. It should be noted that when the molten aluminum enters the inlet section from the storage section, the one-way baffle 300 allows the molten aluminum to flow in a laminar flow along the inner wall of the channel 200 into the forming chamber. As a result, the molten aluminum does not fill the channel 200 when it enters; instead, space is reserved at the top of the channel 200 for the air inside the forming chamber to be discharged.

[0067] Specifically, when the molten aluminum flows along the inner wall of the channel 200, the molten aluminum mainly occupies the lower space of the channel 200, while the top of the channel 200 can retain an exhaust space not occupied by the molten aluminum. After being compressed by the gradually entering molten aluminum, the air in the forming chamber can move along the exhaust space at the top of the channel 200 toward the exhaust hole 205, thus forming a flow state of liquid entering from the bottom and exhausting from the top.

[0068] For example, as the fixed mold 106, the moving mold 108, and the injection pipe gradually tilt from a horizontal to a vertical position, the molten aluminum flows towards the forming chamber along the lower inner wall of the channel 200 under its own gravity. Meanwhile, air, being less dense than molten aluminum, can move in the opposite direction along the space above the molten aluminum surface and enter the vent 205 connected to the channel 200. This method reduces the likelihood of molten aluminum and air colliding or mixing.

[0069] refer to Figure 8 As shown, an exhaust pipe 206 communicating with an exhaust port 205 is fixedly installed on the inner wall of the second half-pipe 202 to discharge the gas in the forming chamber when the aluminum liquid flows into the forming chamber.

[0070] Specifically, one end of the exhaust pipe 206 is connected to the exhaust port 205, and the other end extends outward from the injection pipe, allowing the gas discharged from the exhaust port 205 to be discharged to the outside of the device along the exhaust pipe 206. The exhaust pipe 206 can extend and limit the gas discharge path, reducing the possibility of the discharged gas spreading arbitrarily inside the injection pipe.

[0071] The exhaust pipe 206 includes an inclined section 400, a reaction section 401, and an outlet section 402. The reaction section 401 is provided with two symmetrically arranged shape memory metal springs 403 to adjust the size of the internal ventilation cross section of the exhaust pipe 206 according to the temperature of the exhaust gas.

[0072] The inclined section 400 is used to connect with the exhaust port 205 and guide the discharged gas; the reaction section 401 is used to install the shape memory metal spring 403 and form the area for gas temperature change; the outlet section 402 is used to continue to outlet the gas that has passed through the reaction section 401 to the outside of the device.

[0073] Specifically, two shape memory metal (MMM) springs 403 are positioned opposite each other inside the reaction section 401. When the exhaust gas passes through the reaction section 401, it comes into contact with or is heated by the MMM springs 403. Upon heating, the MMM springs 403 deform to correspond to their preset shape, changing the distance between the two MMM springs 403 and thus adjusting the ventilation cross-section of the reaction section 401. By adjusting the ventilation cross-section of the exhaust pipe 206 using the two MMM springs 403, the exhaust state of the exhaust pipe 206 can be synchronized with the gas temperature during the casting process.

[0074] Furthermore, when the high-temperature gas passes through the reaction section 401, the shape memory metal spring 403 can change the size of the exhaust cross section of the exhaust pipe according to a pre-set deformation direction; when the gas temperature decreases, the shape memory metal spring 403 can gradually recover. This allows for the regulation of the gas flow state within the exhaust pipe 206 and reduces the possibility of external impurities reversing into the molding chamber via the exhaust pipe 206.

[0075] Specifically, the two shape memory metal springs 403 can be configured to move away from each other after being heated by high-temperature gas, thereby increasing the ventilation cross-section between them. This allows the high-temperature gas generated during the filling process to pass through the reaction section 401 more quickly. For example, in the non-casting state, the two shape memory metal springs 403 can maintain a relatively small gap to reduce the reverse entry of external impurities such as dust and debris into the exhaust port 205 and the molding chamber via the outlet section 402 and the reaction section 401. During the casting process, after the shape memory metal springs 403 are deformed by heat, the gas can pass through according to the preset ventilation state. Alternatively, according to actual venting needs, the two shape memory metal springs 403 can be configured to move closer to each other after heating, thereby reducing the ventilation cross-section and limiting the gas discharge speed. The specific deformation direction of the shape memory metal springs 403 can be set according to the venting requirements of the molding chamber.

[0076] It should be noted that the shape memory metal spring 403 adjusts the ventilation section of the exhaust pipe 206 by utilizing its own characteristics of heat deformation and cooling recovery. There is no need to set up a separate detection element for detecting gas temperature, nor is there a need to set up a power element for driving the shape memory metal spring 403 to move, thereby simplifying the adjustment structure inside the exhaust pipe 206.

[0077] Combination Figure 6 and Figure 7 As shown, the inner wall of the first half-pipe 201 is provided with a mounting groove 301, and a limit ball 302 is provided inside the mounting groove 301. A return spring 303 is also provided on the inner wall of the mounting groove 301. An arc-shaped plate 304 is fixedly installed on the outer wall of the one-way baffle 300. The bottom surface of the exhaust pipe 206 is provided with a groove 305 for limiting the one-way rotation of the arc-shaped plate 304, and the inner wall of the groove 305 is rotatably fitted with the outer wall of the one-way baffle 300.

[0078] Specifically, by Figure 4 As shown, the structure on one side of the groove 305 can restrict the reverse movement of the arc plate 304, thereby restricting the one-way baffle 300 from rotating in the opposite direction toward the liquid storage section, so that the one-way baffle 300 can only open in the direction of the molding chamber.

[0079] It should be noted that the limiting ball 302 and the return spring 303 are used to provide initial limiting function, so that during the initial tilting process, the one-way baffle 300 can be in a small opening state under the obstruction of the limiting ball 302 and the return spring 303. When the rotating mechanism drives the fixed mold 106 and the moving mold 108 to tilt as a whole to the preset angle, the one-way baffle 300 breaks through the obstruction of the limiting ball 302 and the return spring 303, and the arc plate 304 presses the limiting ball 302 into the mounting groove 301, and the one-way baffle 300 rotates to a large opening state.

[0080] Furthermore, switching from a small opening to a large opening creates a two-stage process for the molten aluminum to enter the mold, starting with a slow flow and then increasing the flow rate. In the initial stage of filling, the smaller flow rate helps to expel most of the air from the molding chamber; as filling continues, the larger opening allows the remaining molten aluminum to flow smoothly into the molding chamber, thus balancing stable filling and efficient mold filling.

[0081] Back Figure 1 As shown, the rotating mechanism includes a support base 101 fixedly mounted on the base 100, a rotating frame 102 rotatably mounted on the support base 101, a first fixed plate 104 fixedly mounted on the outer wall of the rotating frame 102, a second fixed plate 105 fixedly mounted on the outer wall of the rotating frame 102, a movable plate 107 movably disposed between the first fixed plate 104 and the second fixed plate 105, a second telescopic rod 109 fixedly mounted on the first fixed plate 104, and a first telescopic rod 103 hinged to the base 100. The movable end of the second telescopic rod 109 is fixedly connected to the outer wall of the movable plate 107, and the movable end of the first telescopic rod 103 is rotatably connected to the outer wall of the rotating frame 102. A movable mold 108 is fixedly mounted on the side of the movable plate 107 near the second fixed plate 105, and a fixed mold 106 is fixedly mounted on the side of the second fixed plate 105 near the first fixed plate 104.

[0082] When the first telescopic rod 103 extends or retracts, its movable end applies a pushing or pulling force to the rotating frame 102, causing the rotating frame 102 to rotate around its rotational connection position with the support base 101, thereby realizing the switching between the fixed mold 106, the moving mold 108, and the injection pipe in a horizontal and vertical state.

[0083] When the second telescopic rod 109 extends, it can push the movable plate 107 and the moving mold 108 toward the fixed mold 106, so that the moving mold 108 and the fixed mold 106 are closed; when the second telescopic rod 109 shortens, it can drive the movable plate 107 and the moving mold 108 away from the fixed mold 106, so that the moving mold 108 and the fixed mold 106 are separated.

[0084] Working principle:

[0085] First, the movable plate 107 is moved towards the fixed mold 106 by the second telescopic rod 109, causing the movable mold 108 mounted on the movable plate 107 to close with the fixed mold 106 mounted on the second fixed plate 105, forming a molding chamber. Simultaneously, the second half-tube 202 moves closer to the first half-tube 201 along with the movable mold 108, so that the first half-tube 201 and the second half-tube 202 together form the injection pipe. Then, the rotating frame 102 is rotated by the first telescopic rod 103, bringing the fixed mold 106, the movable mold 108, and the injection pipe into a horizontal position.

[0086] In a horizontal position, molten aluminum is poured from the pouring cylinder 203 into the casting pipe. At this time, the one-way baffle 300 remains closed, so that the molten aluminum is temporarily stored in the storage section formed by the storage box 204 and the corresponding area of ​​the casting pipe, preventing the molten aluminum from directly rushing into the channel 200 and the forming chamber.

[0087] During pouring, the first telescopic rod 103 drives the rotating frame 102 to rotate, causing the fixed mold 106, the moving mold 108, and the pouring pipe to tilt from a horizontal to a vertical position. Initially, the molten aluminum in the storage section exerts a pushing force on the one-way baffle 300. Under the constraint of the limiting ball 302 and the return spring 303, the one-way baffle 300 forms a small opening, allowing a small amount of molten aluminum to flow smoothly into the forming chamber along the lower inner wall of the channel 200. When the tilt reaches the preset state, the arc-shaped plate 304 presses the limiting ball 302 into the mounting groove 301, causing the one-way baffle 300 to rotate to a large opening state, allowing the remaining molten aluminum in the storage section to continue flowing into the forming chamber. The groove 305 restricts the rotation direction of the arc-shaped plate 304, ensuring that the one-way baffle 300 can only open towards the forming chamber.

[0088] When molten aluminum enters the forming chamber through channel 200, it mainly flows along the lower part of channel 200, while the top of channel 200 retains space for venting. Air within the forming chamber, compressed by the molten aluminum, is discharged sequentially through channel 200, vent 205, and vent pipe 206. As the discharged gas passes through the inclined section 400, reaction section 401, and outlet section 402 of vent pipe 206, the shape memory metal spring 403 within the reaction section 401 deforms according to the gas temperature, adjusting the ventilation cross-section inside vent pipe 206.

[0089] After the molten aluminum fills the forming chamber, the first telescopic rod 103 keeps the rotating frame 102 in the corresponding position, and the molten aluminum solidifies and forms under the action of gravity. After the aluminum part is formed, the first telescopic rod 103 drives the rotating frame 102 to rotate in the opposite direction, so that the fixed mold 106, the moving mold 108 and the injection pipe return to the horizontal state, and the one-way baffle 300 returns to the closed position under its own gravity.

[0090] Finally, the second telescopic rod 109 moves the movable plate 107 away from the fixed mold 106, causing the movable mold 108 to separate from the fixed mold 106, and at the same time, causing the second half-tube 202 to separate from the first half-tube 201, so as to remove the formed aluminum part and clean the device.

[0091] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gravity casting method for aluminum parts, characterized in that, Includes the following steps: Step 1: Close the fixed mold and the moving mold. The internal cavities of the two molds together form the molding chamber. The injection pipes on the fixed mold and the moving mold are connected to the molding chamber. The fixed mold, the moving mold and the injection pipes are kept in a horizontal state by a rotating mechanism. Step 2: Pour the molten aluminum into the pouring pipe. With the one-way baffle inside the pouring pipe closed, the molten aluminum is stored in the liquid storage section upstream of the one-way baffle. Step 3: Drive the fixed mold, moving mold and injection pipe to tilt from horizontal to vertical by the rotating mechanism. During the tilting process, the aluminum liquid stored in the liquid storage section exerts a thrust on the one-way baffle. Under the action of the thrust of the aluminum liquid and its own gravity, the one-way baffle opens towards the forming chamber so that the aluminum liquid flows into the forming chamber. Step 4: The molten aluminum entering the forming chamber fills and solidifies under the action of gravity; Step 5: After the aluminum part is formed, the fixed mold, moving mold and injection pipe are rotated back to the horizontal state by the rotating mechanism. Finally, the fixed mold and moving mold are separated and the formed aluminum part is taken out.

2. A gravity casting forming apparatus for aluminum parts, applied to the gravity casting forming method for aluminum parts as described in claim 1, comprising a base, a fixed mold, a movable mold, and a rotating mechanism, wherein the fixed mold and the movable mold, when closed, form a forming chamber for forming aluminum parts, and the outer walls of the fixed mold and the movable mold are provided with injection pipes communicating with the forming chamber, and the rotating mechanism is disposed on the base for driving the fixed mold, the movable mold, and the injection pipes to tilt between a horizontal state and a vertical state, characterized in that: The injection pipe is equipped with a one-way baffle, which divides the injection pipe into a liquid storage section located upstream of the one-way baffle and a liquid inlet section located downstream of the one-way baffle. When the casting pipe is in a horizontal state, the one-way baffle remains closed so that the molten aluminum poured from the inlet end of the casting pipe is stored in the storage section. As the casting pipe tilts from a horizontal state to a vertical state, the one-way baffle opens in one direction toward the forming chamber under the thrust of the molten aluminum and its own gravity, so that the molten aluminum stored in the storage section flows into the forming chamber through the inlet section.

3. The gravity casting apparatus for aluminum parts according to claim 2, characterized in that: The injection pipe includes a first half-pipe fixedly installed on the outer wall of the fixed mold, a second half-pipe fixedly installed on the outer wall of the moving mold, a liquid pouring cylinder fixedly installed on the top surface of the second half-pipe, and a liquid storage box fixedly installed on the bottom surface of the first half-pipe for storing liquid. When the fixed mold and the moving mold are closed, the first half-pipe and the second half-pipe are also closed to form the injection pipe.

4. The gravity casting apparatus for aluminum parts according to claim 3, characterized in that: The one-way baffle is hinged to the inner wall of the first half-tube.

5. The gravity casting apparatus for aluminum parts according to claim 4, characterized in that: The fixed mold has a channel for liquid inlet on the side near the first half-tube, which communicates with the molding chamber. The moving mold has an exhaust hole for exhaust on the side near the second half-tube, which communicates with the channel.

6. The gravity casting apparatus for aluminum parts according to claim 5, characterized in that: The inner wall of the second half-tube is fixedly equipped with an exhaust pipe that communicates with the exhaust hole, so as to discharge the gas in the forming chamber when the aluminum liquid flows into the forming chamber.

7. The gravity casting apparatus for aluminum parts according to claim 6, characterized in that: The exhaust pipe includes an inclined section, a reaction section, and an outlet section. The reaction section is internally equipped with two symmetrically arranged shape memory metal springs.

8. The gravity casting apparatus for aluminum parts according to claim 6, characterized in that: The inner wall of the first half-tube is provided with an installation groove, the inside of the installation groove is provided with a limit ball, and the inner wall of the installation groove is also provided with a return spring.

9. The gravity casting apparatus for aluminum parts according to claim 8, characterized in that: An arc-shaped plate is fixedly installed on the outer wall of the one-way baffle, and a groove is opened on the bottom surface of the exhaust pipe to limit the one-way rotation of the arc-shaped plate, and the inner wall of the groove is rotatably fitted with the outer wall of the one-way baffle.

10. The gravity casting apparatus for aluminum parts according to claim 2, characterized in that: The rotating mechanism includes a support base fixedly mounted on the base, a rotating frame rotatably mounted on the support base, a first fixed plate fixedly mounted on the outer wall of the rotating frame, a second fixed plate fixedly mounted on the outer wall of the rotating frame, a movable plate movably disposed between the first and second fixed plates, a second telescopic rod fixedly mounted on the first fixed plate, and a first telescopic rod hinged to the base. The movable end of the second telescopic rod is fixedly connected to the outer wall of the movable plate, and the movable end of the first telescopic rod is rotatably connected to the outer wall of the rotating frame. The movable mold is fixedly mounted on the side of the movable plate near the second fixed plate, and the fixed mold is fixedly mounted on the side of the second fixed plate near the first fixed plate.

Images