Exhaust device for die-casting process

Abstract

The invention discloses an exhaust device for a die-casting process, which solves the problem of poor exhaust effect caused by easy blockage of an exhaust channel of the existing exhaust device for the die-casting process, and specifically comprises a movable die exhaust plate and a fixed die exhaust plate buckled above the movable die exhaust plate, an exhaust channel is arranged between the movable mold exhaust plate and the fixed mold exhaust plate; the height of the exhaust channel is gradually reduced from the air inlet end to the air outlet end; the longitudinal section of the exhaust channel is of a tooth structure, and the transverse section of the exhaust channel is of a W-shaped structure. The height of the exhaust channel is gradually reduced from the gas inlet end to the gas outlet end, so that when aluminum liquid enters the exhaust channel along with gas, the section of the exhaust channel is gradually narrowed, the flowing resistance is increased, the flowing speed is reduced, and the aluminum liquid is difficult to smoothly flow to a vacuumizing opening of a vacuum pump, thereby avoiding blockage and improving the exhaust efficiency; the defects of air holes, looseness and the like formed by residual gas in the casting solidification process are avoided, and the strength and sealing performance of the casting are improved.

Description

Technical Field

[0001] The present invention relates to an exhaust device, and more particularly to an exhaust device for die-casting processes. Background Art

[0002] The die-casting process is a casting method that injects molten metal into a mold cavity rapidly under high pressure and solidifies it under pressure. With the characteristics of high production efficiency, high dimensional accuracy, and excellent surface quality, it has been widely used in many fields such as automobile manufacturing, electronics industry, and aerospace. However, if the gas in the mold cavity cannot be discharged in time during die-casting, it will cause casting defects such as pores and porosity, seriously affecting the quality of the casting. Therefore, vacuum pumping technology has been introduced into the die-casting process to quickly discharge the gas in the cavity through a vacuum pump.

[0003] Early die-casting molds mainly exhausted gas by opening exhaust grooves on the parting surface. This method has a simple structure and low cost, but the exhaust effect is limited. The depth and width of the exhaust grooves need to be strictly controlled. If they are too deep or too wide, it is easy for the molten metal to leak, and if they are too shallow or too narrow, the exhaust effect is not good. In addition, for castings with complex shapes, it is difficult to arrange the exhaust grooves to meet the comprehensive exhaust requirements. Although the existing exhaust technologies can discharge the gas in the cavity to a certain extent, for castings with complex structures, it is still difficult to ensure that the gas is completely discharged. The residual gas will form defects such as pores and porosity during the solidification of the casting, reducing the strength and tightness of the casting and affecting the service performance of the casting. Especially when producing thin-walled and complex-shaped castings, the problem of poor exhaust is particularly prominent.

[0004] Chinese Utility Model Patent with Publication No. CN 207982277 U discloses "A New Exhaust Structure for Die-Casting Molds", which includes a moving mold, a moving mold exhaust plate, a fixed mold, and a fixed mold exhaust plate. The moving mold exhaust plate is inlaid on the moving mold, and a convex guiding groove is provided on the moving mold exhaust plate. The fixed mold is below the moving mold, and the fixed mold exhaust plate is inlaid on the fixed mold. A concave guiding groove is provided on the fixed mold exhaust plate. The convex guiding groove and the concave guiding groove are arranged in a staggered manner relative to each other. An exhaust passage is provided between the moving mold exhaust plate and the fixed mold exhaust plate. A number of sound-absorbing holes are provided on the upper and lower sides of the exhaust passage. A buffer zone is provided on the right side of the exhaust passage, and an exhaust port is provided at the right end of the exhaust passage, and a wind direction strip is pasted at the exhaust port. In this utility model, the structure is simple. The convex guiding grooves on the moving mold exhaust plate and the fixed mold exhaust plate are arranged in a staggered manner relative to the concave guiding grooves, which balances the air pressure in the exhaust passage during exhaust. At the same time, the wind direction strip can intuitively show the exhaust progress. However, there is a key problem in the actual application of this exhaust structure: the aluminum liquid is easy to enter the exhaust passage under high pressure, block the vacuum port, and cause the exhaust to fail. Once blocked, the vacuum system cannot work properly, and the gas in the cavity cannot be discharged, seriously affecting the quality of the casting. And cleaning the blockage requires shutting down the machine and disassembling the mold, increasing the production cost and reducing the production efficiency. Summary of the Invention

[0005] In order to solve the technical problem that the exhaust passage of the existing exhaust device for die-casting process is prone to blockage, resulting in poor exhaust effect, and residual gas will form defects such as pores and looseness during the solidification process of the casting, reducing the strength and sealing performance of the casting and affecting the service performance of the casting, the present invention provides an exhaust device for die-casting process.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An exhaust device for die-casting process is arranged between a die-casting mold and a vacuum pump;

[0008] The special feature is that:

[0009] It includes a moving die exhaust plate and a fixed die exhaust plate buckled above the moving die exhaust plate;

[0010] An exhaust passage is provided between the moving die exhaust plate and the fixed die exhaust plate;

[0011] The height of the exhaust passage gradually decreases from its intake end to its outlet end;

[0012] Define the direction from the intake end to the outlet end of the exhaust passage as the longitudinal direction of the exhaust passage; the longitudinal section of the exhaust passage is a toothed structure, and its transverse section is a W-shaped structure.

[0013] Furthermore, a first buffer groove with an upward opening and communicating with the exhaust passage is provided on the moving die exhaust plate;

[0014] The first buffer groove is arranged close to the intake end of the exhaust passage.

[0015] Furthermore, the first buffer groove transversely penetrates the entire exhaust passage.

[0016] Furthermore, a second buffer groove with a downward opening and communicating with the exhaust passage is provided on the fixed die exhaust plate;

[0017] The second buffer groove is arranged close to the outlet end of the exhaust passage.

[0018] Furthermore, the second buffer groove transversely penetrates the entire exhaust passage.

[0019] Furthermore, the intake end port of the exhaust passage is arranged on the moving die exhaust plate;

[0020] The outlet end port of the exhaust passage is arranged on the fixed die exhaust plate and is located on the inner wall of the second buffer groove.

[0021] Furthermore, a baffle protruding upward is provided on the moving die exhaust plate for inserting into the second buffer groove and blocking the outlet end port of the exhaust passage;

[0022] A gap communicating with the exhaust passage is provided between the outer wall of the baffle plate and the inner wall of the second buffer groove.

[0023] Furthermore, cooling water channels are provided inside both the moving die exhaust plate and the fixed die exhaust plate.

[0024] Furthermore, thimble holes penetrating the upper and lower parts are provided on the moving die exhaust plate;

[0025] The top of the thimble hole communicates with the first buffer groove on the moving die exhaust plate.

[0026] Furthermore, the volume of the first buffer groove is 3 to 8 times the volume of the vertical section of the exhaust passage near the air inlet end.

[0027] Advantages of the present invention:

[0028] 1. An exhaust device for die-casting process provided by the present invention has a height of the exhaust passage gradually decreasing from its air inlet end to its air outlet end. When the molten aluminum enters the exhaust passage along with the gas, the flow resistance increases due to the gradually narrowing cross-section of the exhaust passage, the flow velocity decreases, and it is difficult to flow smoothly to the vacuum pumping port of the vacuum pump, thereby avoiding blockage, improving the exhaust efficiency, preventing residual gas from forming defects such as pores and looseness during the solidification of the casting, improving the strength and sealing performance of the casting, and meeting the requirements of modern die-casting process for high-quality castings.

[0029] 2. An exhaust device for die-casting process provided by the present invention has the longitudinal cross-section of the exhaust passage set as a tooth structure and the transverse cross-section set as a W-shaped structure, so that the exhaust passage has a large inner wall area and a small opening area. After the molten aluminum enters, it diffuses to both sides under the action of the W-shaped cross-section, further increasing the flow resistance, decreasing the flow velocity, reducing the erosion of the exhaust passage by the molten aluminum, and reducing the maintenance frequency.

[0030] 3. An exhaust device for die-casting process provided by the present invention is provided with a first buffer groove on the moving die exhaust plate and a second buffer groove on the fixed die exhaust plate. The settings of the first buffer groove and the second buffer groove can slow down the speed of the molten aluminum and gas entering the exhaust passage, ensure that the gas and molten aluminum can enter the exhaust passage smoothly, and avoid damage to the exhaust passage caused by high-speed impact.

[0031] 4. An exhaust device for die-casting process provided by the present invention is provided with a baffle plate on the moving die exhaust plate, and this baffle plate can prevent tiny molten aluminum particles that may pass through the exhaust passage from entering the vacuum pump and damaging the equipment.

[0032] 5. An exhaust device for die-casting process provided by the present invention is also provided with cooling water channels, which can effectively cool the moving die exhaust plate and the fixed die exhaust plate in a timely manner.

[0033] 6. An exhaust device for die-casting process provided by the present invention is applicable to various die-casting molds. Whether it is a casting with a simple shape or a complex shape, good exhaust effect and anti-blocking function can be achieved by reasonably arranging the exhaust plate and designing the parameters of the exhaust channel. At the same time, the material and structural design of the exhaust plate have high versatility, can be selected and adjusted according to different die-casting process requirements, and have significant cost-effective advantages during long-term use, which is conducive to popularization and application.

[0034] 7. An exhaust device for die-casting process provided by the present invention is also provided with ejector pin holes, so that it can be easily disassembled with the help of external force during disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a longitudinal sectional view of an embodiment of an exhaust device for die-casting process of the present invention;

[0036] Figure 2 is a longitudinal sectional schematic diagram of the exhaust channel in the embodiment of the present invention;

[0037] Figure 3 is a transverse sectional schematic diagram of the exhaust channel in the embodiment of the present invention;

[0038] Figure 4 is a three-dimensional structural schematic diagram of the moving die exhaust plate in the embodiment of the present invention;

[0039] Figure 5 is a side view of the moving die exhaust plate in the embodiment of the present invention;

[0040] Figure 6 is a top view of the moving die exhaust plate in the embodiment of the present invention;

[0041] Figure 7 is a three-dimensional structural schematic diagram of the fixed die exhaust plate in the embodiment of the present invention;

[0042] Figure 8 is a side view of the fixed die exhaust plate in the embodiment of the present invention;

[0043] Figure 9 is a top view of the fixed die exhaust plate in the embodiment of the present invention.

[0044] Reference Numerals in the Drawings:

[0045] 1 - Moving die exhaust plate, 11 - First buffer groove, 12 - Baffle, 13 - Ejector pin hole;

[0046] 2 - Fixed die exhaust plate, 21 - Second buffer groove;

[0047] 3 - Exhaust channel, 31 - Intake end, 32 - Outlet end;

[0048] 4 - Cooling water channel. Detailed implementation mode

[0049] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0050] An exhaust device for die-casting process provided by an embodiment of the present invention is arranged between a die-casting mold and a vacuum pump; as Figure 1 shown, the exhaust device includes a moving die exhaust plate 1 and a fixed die exhaust plate 2 buckled above the moving die exhaust plate 1; an exhaust passage 3 is arranged between the moving die exhaust plate 1 and the fixed die exhaust plate 2; the moving die exhaust plate 1 and the fixed die exhaust plate 2 are made of high-temperature resistant and high-strength alloy materials to ensure that they can withstand the impact and pressure of high-temperature aluminum liquid during die-casting.

[0051] As Figure 2 and Figure 3 shown, the exhaust passage 3 is a gas flow passage. During use, its inlet end 31 will receive the gas in the cavity and the aluminum liquid that may be mixed in, and its outlet end 32 is connected to a vacuum pump for exhausting gas. The exhaust passage 3 is divided into multiple sections along the gas flow direction, and the cross-sectional thicknesses of each section are different. Specifically, from the inlet end 31 to the outlet end 32, the height of the exhaust passage 3 generally gradually decreases; specifically, the cross-sectional height T1 of the first section of the exhaust passage 3 near the inlet end 31 is relatively large, which can be set as T1 = 3 mm; as the gas flows towards the outlet end 32, the cross-sectional height T2 of the second section of the exhaust passage 3 decreases to T2 = 1 mm; the cross-sectional height T3 of the third section of the exhaust passage 3 further decreases to T3 = 0.8 mm, and near the outlet end 32, the cross-sectional height T4 of the exhaust passage 3 further decreases to T4 = 0.5 mm, and at the same time, the thickness T5 of the vertical exhaust passage is 1 mm. This design of gradually changing cross-sectional height makes the aluminum liquid increase the flow resistance and reduce the flow speed due to the gradually narrowing cross-section of the exhaust passage 3 when entering the exhaust passage 3, and it is difficult to flow smoothly to the vacuum pumping port, thus avoiding blockage.

[0052] The direction from the inlet end 31 to the outlet end 32 of the exhaust passage 3 is the longitudinal direction of the exhaust passage 3; the longitudinal cross-section of the exhaust passage 3 is a tooth structure, and its transverse cross-section is a W-shaped structure to achieve the effect of unsmooth aluminum liquid flow. The exhaust passage with a W-shaped cross-section has a relatively large bottom area and a relatively small opening area. After the aluminum liquid enters, it diffuses to both sides under the action of the W-shaped cross-section, further increasing the flow resistance and reducing the flow speed.

[0053] As Figure 4 , Figure 5 and Figure 6As shown in the figure, in order to slow down, a first buffer groove 11 with an upward opening and communicating with the exhaust passage 3 is provided on the moving die exhaust plate 1; the first buffer groove 11 is arranged near the intake end 31 of the exhaust passage 3, and the first buffer groove 11 transversely penetrates the entire exhaust passage 3; the first buffer groove 11 is used to slow down the speed of the molten aluminum and gas entering the exhaust passage 3, ensuring that the gas and molten aluminum can smoothly enter the exhaust passage 3 and avoiding damage to the exhaust passage 3 caused by high-speed impact. The volume of the first buffer groove 11 can be adjusted according to the size of the die-casting mold and the filling speed of the molten aluminum. The volume of the first buffer groove 11 is 3 to 8 times the volume of the vertical section of the exhaust passage 3 near the intake end 31. In this embodiment, 8 times is selected; the sum of the thicknesses of the first buffer groove 11 and the corresponding exhaust passage 3, T6 = 8 mm. The port of the intake end 31 of the exhaust passage 3 is arranged on the moving die exhaust plate 1.

[0054] As Figure 7 , Figure 8 and Figure 9 shown, based on the same principle, in this embodiment, a second buffer groove 21 with a downward opening and communicating with the exhaust passage 3 is provided on the fixed die exhaust plate 2; the second buffer groove 21 is arranged near the outlet end 32 of the exhaust passage 3. The second buffer groove 21 transversely penetrates the entire exhaust passage 3. The port of the outlet end 32 of the exhaust passage 3 is arranged on the fixed die exhaust plate 2, on the inner wall of the second buffer groove 21, and a filter screen is provided at the outlet end 32.

[0055] An upward convex baffle 12 is provided on the moving die exhaust plate 1, which can be inserted into the second buffer groove 21. The baffle 12 corresponds to the port of the outlet end 32 and can block the port of the outlet end 32 of the exhaust passage 3 to prevent tiny molten aluminum particles that may pass through the exhaust passage from entering the vacuum pump and damaging the equipment; a gap communicating with the exhaust passage 3 is provided between the outer wall of the baffle 12 and the inner wall of the second buffer groove 21 to ensure the overall connection of the exhaust passage 3.

[0056] A thimble hole 13 penetrating through the upper and lower parts is provided on the moving die exhaust plate 1; the top of the thimble hole 13 communicates with the first buffer groove 11 on the moving die exhaust plate 1.

[0057] In order to effectively cool down, cooling water channels 4 are provided inside both the moving die exhaust plate 1 and the fixed die exhaust plate 2.

[0058] Working principle:

[0059] During the die-casting process, when the molten aluminum fills the cavity of the die-casting mold, the gas in the cavity and the molten aluminum that may be mixed in enter the exhaust passage 3 through the air inlet end 31, and then enter the first buffer tank 11. In the first buffer tank 11, the speed of the molten aluminum and the gas slows down, and then it smoothly enters the exhaust passage 3 through the gradual transition section. Since the thickness of each cross-section of the exhaust passage 3 gradually decreases from the air inlet end 31 to the air outlet end 32, the resistance of the molten aluminum increases gradually when flowing in the exhaust passage 3, and the speed decreases. As the flow speed of the molten aluminum slows down, the kinetic energy decreases, and it is difficult to overcome the resistance of the exhaust passage 3 and continue to flow towards the vacuum port, so it deposits in the exhaust passage 3, avoiding blocking the vacuum port. And the gas smoothly passes through the exhaust passage 3 under the action of the vacuum system, and is extracted from the air outlet end 32 after being filtered by the filter screen, realizing the effective discharge of the gas in the mold cavity and improving the quality of the casting.

[0060] Through the design of the gradual change of the thickness of the exhaust passage, the flow of the molten aluminum in the exhaust passage is not smooth, reducing the possibility of the molten aluminum reaching the vacuum port, fundamentally solving the problem that the vacuum port is easily blocked, ensuring the smooth progress of the vacuum die-casting process, improving the production efficiency, and reducing the mold maintenance and cleaning costs caused by blockage.

[0061] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. An exhaust device for die-casting process, which is arranged between a die-casting mold and a vacuum pump; It is characterized in that: It includes a moving die exhaust plate (1) and a fixed die exhaust plate (2) buckled above the moving die exhaust plate (1); An exhaust passage (3) is provided between the moving die exhaust plate (1) and the fixed die exhaust plate (2); The height of the exhaust passage (3) gradually decreases from its air inlet end (31) to its air outlet end (32); Define the direction from the air inlet end (31) to the air outlet end (32) of the exhaust passage (3) as the longitudinal direction of the exhaust passage (3); the longitudinal section of the exhaust passage (3) is a tooth structure, and its transverse section is a W-shaped structure.

2. The exhaust device for die-casting process according to claim 1, characterized in that: A first buffer groove (11) with an upward opening and communicating with the exhaust passage (3) is provided on the moving die exhaust plate (1); The first buffer groove (11) is arranged close to the air inlet end (31) of the exhaust passage (3).

3. The exhaust device for die-casting process according to claim 2, characterized in that: The first buffer groove (11) transversely penetrates the entire exhaust passage (3).

4. The exhaust device for die-casting process according to claim 3, characterized in that: A second buffer groove (21) with a downward opening and communicating with the exhaust passage (3) is provided on the fixed die exhaust plate (2); The second buffer groove (21) is arranged close to the air outlet end (32) of the exhaust passage (3).

5. The exhaust device for die-casting process according to claim 4, characterized in that: The second buffer groove (21) transversely penetrates the entire exhaust passage (3).

6. The exhaust device for die-casting process according to claim 5, characterized in that: The port of the air inlet end (31) of the exhaust passage (3) is arranged on the moving die exhaust plate (1); The port of the air outlet end (32) of the exhaust passage (3) is arranged on the fixed die exhaust plate (2) and is located on the inner wall of the second buffer groove (21).

7. The exhaust device for die-casting process according to claim 6, characterized in that: An upward protruding baffle (12) is provided on the moving die exhaust plate (1) for inserting into the second buffer groove (21) and blocking the port of the air outlet end (32) of the exhaust passage (3); A gap communicating with the exhaust passage (3) is provided between the outer wall of the baffle (12) and the inner wall of the second buffer groove (21).

8. The exhaust device for die-casting process according to claim 7, characterized in that: Cooling water channels (4) are provided inside both the moving die exhaust plate (1) and the fixed die exhaust plate (2).

9. The exhaust device for die-casting process according to claim 8, characterized in that: A thimble hole (13) penetrating through the upper and lower parts is provided on the moving die exhaust plate (1); The top of the thimble hole (13) communicates with the first buffer groove (11) on the moving die exhaust plate (1).

10. The exhaust device for die-casting process according to claim 9, characterized in that: The volume of the first buffer groove (11) is 3 to 8 times the volume of the vertical section of the exhaust passage (3) near the air inlet end (31).

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