Exhaust structure of casting mold

Abstract

The invention relates to the technical field of casting molds, in particular to a casting mold exhaust structure which comprises a main exhaust passage, the main exhaust passage is communicated with a cavity of a mold, an exhaust assembly is arranged at the outlet end of the main exhaust passage, an opening and closing assembly is arranged at the inlet end of the main exhaust passage, and the opening and closing assembly comprises an elastic piece and a sealing wafer. The two sides of the elastic piece abut against the inner wall of the main exhaust passage, the elastic piece is bent downwards to abut against the sealing wafer, the periphery of the sealing wafer abuts against the inner wall of the main exhaust passage in a sealed mode, a breaking joint which is separated end to end is formed in the middle of the sealing wafer, and the structure, in the half-surrounded area of the breaking joint, of the sealing wafer can have the tendency of tilting upwards under the action of air pressure. And an auxiliary exhaust passage is arranged on the mold, is communicated with the cavity of the mold, and is spirally distributed around the main exhaust passage. The main exhaust passage and the auxiliary exhaust passage are matched with each other, gas accumulation is effectively eliminated through multi-path exhaust, the turbulence phenomenon is reduced, molten metal is stably filled, and the defects of air holes, looseness and the like in a casting are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of casting moulds, and in particular to a casting mould exhaust structure. Background Art

[0002] In modern casting technology, the performance of the mold exhaust system directly determines the density, surface finish and mechanical properties of the casting. It can be seen that the quality of the mold exhaust system plays a key role in the quality of the casting. During the casting process, if the gas in the cavity cannot be discharged smoothly, it will cause many serious problems.

[0003] The exhaust structure of existing casting molds generally has the disadvantage of a single exhaust path. Traditional designs often rely on only a limited number of straight exhaust holes, and the gas can only be discharged along a fixed and single channel, so that when the molten metal is filling the mold at a high speed, the gas cannot be evacuated quickly, and it is easy to accumulate locally in the cavity, forming a large pressure difference. The pressure difference is the root cause of turbulence. The emergence of turbulence will seriously interfere with the smooth flow of molten metal. Under the influence of turbulence, the flow rate and flow direction of the molten metal continue to change sharply, making it difficult to evenly fill all parts of the cavity. This will not only cause defects such as pores and looseness inside the casting, resulting in a decrease in the strength and density of the casting, but may also form scouring marks on the mold surface due to the turbulent flow of the molten metal, reducing the service life of the mold.

[0004] At the same time, when the molten metal in the cavity enters the cooling stage, the gas pressure in the cavity changes as the temperature drops. The mold may also be hit during the cooling process, causing the internal molten metal to flow. These factors may cause the molten metal to flow back into the exhaust structure, thereby causing the exhaust structure to be blocked. Summary of the invention

[0005] In order to solve the technical problems that the exhaust path of the existing exhaust structure of the casting mold is single, turbulence is easily generated, and the molten metal is easily backflowed into the exhaust hole to cause blockage when cooling, the present invention provides a casting mold exhaust structure.

[0006] To achieve the above object, the technical solution adopted by the present invention is: A casting mold exhaust structure comprises a main exhaust duct, which is connected with a mold cavity of the mold, an exhaust assembly is provided at the outlet end of the main exhaust duct, an opening and closing assembly is provided at the inlet end of the main exhaust duct, the opening and closing assembly comprises an elastic sheet and a sealing disc, both sides of the elastic sheet abut against the inner wall of the main exhaust duct, the elastic sheet is bent downward to abut against the sealing disc, the outer periphery of the sealing disc is sealed against the inner wall of the main exhaust duct, a first separation fracture is provided in the middle of the sealing disc, and the structure of the sealing disc in the semi-enclosed area of ​​the fracture can have a tendency to warp upward under the action of air pressure; a secondary exhaust duct is provided on the mold, which is connected with the mold cavity of the mold, the secondary exhaust duct is spirally distributed around the main exhaust duct, the inner diameter of the secondary exhaust duct is smaller than that of the main exhaust duct, and air plugs are provided at the outlet and inlet ends of the secondary exhaust duct, and a plurality of air holes with a diameter less than 0.2 mm are opened on the air plug.

[0007] The setting of the main exhaust duct and the auxiliary exhaust duct changes the drawback of the single exhaust path of the traditional exhaust structure, provides the main exhaust duct and the auxiliary exhaust duct, forms a graded exhaust, and reduces the generation of turbulence. In the early stage of pouring, the auxiliary exhaust duct establishes a low-resistance exhaust channel in advance to guide the gas to form a swirl and accelerate the discharge. At the peak of filling, when the gas pressure is high, the gas pressure causes the sealing disc to tilt upward in the structure of the semi-enclosed area of ​​the fracture to push the elastic sheet open, open the main exhaust duct, and the degree of upward tilt of the structure in the semi-enclosed area is self-adjusted according to the gas pressure. When the pouring is completed and the air pressure in the cavity is reduced, the sealing disc returns to its original state and seals with the elastic sheet to prevent the reflux of the molten metal. The setting of the vent plug and the vent hole can ensure exhaust while effectively blocking the molten metal from entering the auxiliary exhaust duct to prevent the clogging of the auxiliary exhaust duct.

[0008] As a preferred implementation of a casting mold exhaust structure, the axis of the inlet end of the secondary exhaust duct forms an angle of 15°-25° with the cavity surface, and the axis of the outlet end of the secondary exhaust duct forms an angle of 15°-25° with the outer surface of the mold.

[0009] It allows the gas in the cavity to enter and discharge more smoothly, avoids the formation of vortex at the inlet end of the auxiliary exhaust duct, reduces the discharge resistance of the gas at the outlet end of the auxiliary exhaust duct, improves the gas inlet and outlet efficiency, ensures the smoothness of exhaust, improves the exhaust effect, and reduces the gas accumulation and turbulence in the cavity.

[0010] As a preferred implementation of the exhaust structure of a casting mold, a connecting air channel radially connected to the main exhaust channel is provided on the secondary exhaust channel.

[0011] The connecting airway can realize the gas exchange between the main exhaust duct and the auxiliary exhaust duct. In the initial stage of pouring, a small amount of gas enters the main exhaust duct from the auxiliary exhaust duct through the connecting airway. When the main exhaust duct is opened, the auxiliary exhaust duct guides the gas to enter the main exhaust duct at an accelerated speed, automatically equalizes the pressure, and avoids local high pressure in the airway. When the air pressure in the main exhaust duct suddenly increases, the gas rebounds to the auxiliary exhaust duct through the connecting airway for spiral buffering, and the swirl in the auxiliary exhaust duct and the airflow in the main exhaust duct form a counter-energy dissipation.

[0012] As a preferred implementation method of the exhaust structure of a casting mold, the exhaust assembly includes an exhaust plug, the top of the exhaust plug is a cylindrical structure, the bottom of the exhaust plug is an inverted frustum structure, the outer peripheral surface of the exhaust plug is provided with a plurality of exhaust grooves, the plurality of exhaust grooves are distributed along the circumferential direction of the exhaust plug, and each exhaust groove is only connected to the upper end surface of the exhaust plug; the outlet end of the main exhaust duct is provided with a reducing portion abutting the outer peripheral surface of the exhaust plug; the upper end surface of the exhaust plug is connected to a compression spring, the top end of the compression spring is connected to a compression plate, the bottom of the compression plate is provided with a compression rod connected to the outer surface of the mold, and the compression rod is parallel to the axis of the main exhaust duct.

[0013] When the gas pressure in the main exhaust duct is high, the gas presses against the exhaust plug, the compression spring is compressed and deformed, the exhaust plug moves upward, and the outer peripheral surface of the frustum structure at the bottom of the exhaust plug is separated from the reducer to form an annular gap. The annular gap connects the exhaust groove and the main exhaust duct, so that the gas can be discharged smoothly from the exhaust groove. When the gas pressure decreases, the compression spring resets and the annular gap closes, ensuring the sealing performance of the exhaust plug and the reducer to prevent reflux and leakage of molten metal.

[0014] As a preferred implementation of a casting mold exhaust structure, the clamping plate is a circular plate, and a plurality of clamping rods are provided, and the plurality of clamping rods are distributed along the circumferential direction of the clamping plate.

[0015] The circular clamping plate can distribute the clamping force more evenly, so that the exhaust plug is more balanced when subjected to the clamping force, ensuring the stability of the exhaust plug in the main exhaust duct, and avoiding the exhaust plug from tilting or shifting due to uneven force, thereby affecting the exhaust effect and sealing performance. Several clamping rods distributed along the circumference further enhance the support and fixing effect of the clamping plate, so that the clamping plate can apply pressure to the exhaust plug more stably, ensuring good contact and sealing between the exhaust plug and the reducer, and improving the reliability of the exhaust structure.

[0016] As a preferred implementation method of a casting mold exhaust structure, an annular groove is provided on the outer surface of the mold, the annular groove is coaxially arranged with the clamping plate, the inner wall of the annular groove is provided with an internal thread, the inner side of the clamping rod is provided with an external thread that matches the outer wall of the annular groove, and the clamping rod is threadedly connected to the annular groove.

[0017] The threaded connection makes the connection between the clamping rod and the outer surface of the mold more firm and reliable, which can effectively prevent the clamping rod from loosening or falling off during operation, ensuring the stability and safety of the exhaust structure. At the same time, by rotating the clamping rod, the compression amount of the clamping spring can be easily adjusted, thereby adjusting the sealing pressure between the exhaust plug and the reducer, and flexibly adjusting the exhaust performance and sealing performance of the exhaust structure according to actual work requirements, thereby improving the adaptability and adjustability of the exhaust structure.

[0018] As a preferred implementation of the exhaust structure of a casting mold, the inner wall of the outlet end of the main exhaust passage is provided with a circle of protrusions, and the top of the elastic sheet abuts against the protrusions.

[0019] The setting of the protrusion provides a support point for the elastic sheet, thereby preventing the elastic sheet from entering deep inside the main exhaust duct.

[0020] As a preferred implementation of a casting mold exhaust structure, the inner wall of the main exhaust passage is provided with a plurality of arc-shaped recessed portions.

[0021] The arc-shaped concave portion can change the flow path of the gas in the main exhaust duct, increase the disturbance of the gas flow, make the gas easier to contact with the inner wall of the main exhaust duct during the flow process, promote the impurities in the gas (such as small particles formed by the splash of molten metal, etc.) to adhere to the arc-shaped concave portion, reduce the possibility of impurities entering the exhaust component or the auxiliary exhaust duct, and prevent the exhaust duct from being blocked. At the same time, the arc-shaped concave portion also helps to disperse the pressure of the gas flow, so that the gas flows more evenly in the main exhaust duct, improve the exhaust effect, and reduce the generation of turbulence.

[0022] As a preferred implementation of a casting mold exhaust structure, the melting points of the elastic sheet and the sealing disc are higher than 800°C.

[0023] During the casting process, the temperature of the molten metal is relatively high, and the elastic sheet and sealing disc have a relatively high melting point, so they can maintain good physical and mechanical properties in a high temperature environment and are not easily melted or deformed due to high temperature, thus ensuring that the opening and closing components can always work normally during the entire casting process.

[0024] As a preferred implementation of a casting mold exhaust structure, the inner walls of the main exhaust passage and the auxiliary exhaust passage are provided with a ceramic coating.

[0025] The ceramic coating has excellent properties such as high temperature resistance, wear resistance, and corrosion resistance. It can effectively protect the inner wall of the main exhaust duct and the auxiliary exhaust duct, reduce the scouring and erosion of the inner wall by the metal liquid, and extend the service life of the exhaust duct. At the same time, the ceramic coating has a smooth surface, which can reduce the resistance of gas flow, allowing the gas to flow more smoothly in the exhaust duct, improve exhaust efficiency, further reduce the generation of turbulence, and ensure the quality of castings.

[0026] The beneficial effects of the present invention include: The main exhaust duct and the auxiliary exhaust duct cooperate with each other, and the multi-path exhaust effectively eliminates gas accumulation, greatly reduces turbulence, and allows the metal liquid to fill the mold smoothly. The defects such as pores and looseness inside the casting are significantly reduced, and the strength and density are significantly improved. The opening and closing components use elastic sheets and sealing discs to accurately control exhaust and sealing, prevent the metal liquid from flowing back, and ensure that the exhaust channel is unobstructed. The auxiliary exhaust duct is spirally distributed, and with the setting of the breathable plug, it optimizes the gas inlet and outlet path and enhances the exhaust efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0028] Figure 1 It is a schematic cross-sectional structure diagram of a casting mold exhaust structure in Example 1; Figure 2 is a schematic diagram of the top view of the elastic sheet in Example 1; Figure 3 Schematic diagram of the top view of the sealing wafer in Example 1; Figure 4 This is a schematic cross-sectional structure diagram of a casting mold exhaust structure in Example 2.

[0029] List of parts and reference numerals: 1. Main exhaust duct; 11. Protruding portion; 12. Variable diameter portion; 13. Arc-shaped recessed portion; 2. Mold; 21. Annular groove; 3. Exhaust assembly; 31. Exhaust plug; 32. Exhaust groove; 33. Compression spring; 34. Compression plate; 35. Compression rod; 4. Opening and closing assembly; 41. Elastic sheet; 42. Sealing disc; 421. Break; 5. Auxiliary exhaust duct; 6. Ventilation plug; 7. Connecting air duct. DETAILED DESCRIPTION

[0030] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] Embodiment 1: Reference Figure 1-3This embodiment provides a casting mold exhaust structure, including a main exhaust channel 1, the main exhaust channel 1 is connected to the cavity of the mold 2, the outlet end of the main exhaust channel 1 is provided with an exhaust component 3, and the inlet end of the main exhaust channel 1 is provided with an opening and closing component 4. Figure 1 The outlet end of the main exhaust duct 1 is at the top, and the inlet end is at the bottom. The opening and closing assembly 4 includes an elastic sheet 41 and a sealing disc 42. The casting temperature of the aluminum alloy is between 680°C and 760°C. The melting points of the elastic sheet 41 and the sealing disc 42 are higher than 800°C, and they can maintain good physical and mechanical properties at high temperatures and work stably. The two sides of the elastic sheet 41 abut against the inner wall of the main exhaust duct 1, the elastic sheet 41 bends downward to abut against the sealing disc 42, the outer periphery of the sealing disc 42 abuts against the inner wall of the main exhaust duct 1, and the middle part of the sealing disc 42 is provided with a first separation break 421, and the structure of the sealing disc 42 in the semi-enclosed area of ​​the break 421 can have a tendency to warp upward under the action of air pressure. The break 421 in this embodiment is arc-shaped, and the sealing disc 42 is provided with a protrusion at the bottom of the break 421 to prevent the structure of the sealing disc 42 in the semi-enclosed area of ​​the break 421 from curling downward. The inner wall of the outlet of the main exhaust duct 1 is provided with a circle of protrusions 11, the top of the elastic sheet 41 abuts against the protrusions 11, and the protrusions 11 provide support for the elastic sheet 41. The elastic sheet 41 and the sealing disc 42 are connected to the outlet of the main exhaust duct 1 in an interference fit.

[0032] In this embodiment, the sealing disc 42 in the opening and closing component 4 is provided with a first separation crack 421 in the middle, and the structure in the semi-enclosed area of ​​the crack 421 can have a tendency to tilt upward under the action of gas pressure. During pouring, the gas pressure in the cavity increases. When the pressure reaches a certain level, the structure of the sealing disc 42 in the semi-enclosed area of ​​the crack 421 tilts upward to push the elastic sheet 41 and open the main exhaust channel 1. The tilting degree is self-adjusted according to the gas pressure. After pouring, the gas pressure in the cavity decreases, the sealing disc 42 returns to its original state, and seals with the elastic sheet 41 to prevent the metal liquid from flowing back.

[0033] The mold 2 is provided with a secondary exhaust channel 5, which is connected to the mold cavity of the mold 2. The secondary exhaust channel 5 is spirally distributed around the main exhaust channel 1, and the spiral angle is 30°±5°, balancing the flow resistance and the centrifugal force. The spiral pitch gradient is 2mm-4mm. Multiple secondary exhaust channels 5 can be provided, and multiple secondary exhaust channels 5 are staggered. The axis of the inlet end of the secondary exhaust channel 5 forms an angle of 15°-25° with the surface of the mold cavity, and the axis of the outlet end of the secondary exhaust channel 5 forms an angle of 15°-25° with the outer surface of the mold 2, so that the gas in the mold cavity can enter and discharge more smoothly, avoid the formation of vortex at the inlet end of the secondary exhaust channel 5, reduce the discharge resistance of the gas at the outlet end of the secondary exhaust channel 5, improve the gas inlet and outlet efficiency, and ensure the smoothness of exhaust. The inner diameter of the secondary exhaust duct 5 is smaller than that of the main exhaust duct 1. The outlet and inlet ends of the secondary exhaust duct 5 are both provided with air plugs 6. The air plugs 6 are provided with a number of air holes with a diameter less than 0.2 mm. The diameter of the air holes is small, and the surface tension will form capillary resistance. The surface tension is greater than the flow pressure of the liquid metal, which prevents the metal liquid from seeping out and does not affect the exhaust. When the metal liquid accidentally enters the secondary exhaust duct 5, the metal liquid is separated from the gas under the action of the centrifugal force of the gas vortex in the secondary exhaust duct 5, and it is not easy to block the secondary exhaust duct 5 during the pouring stage, and does not affect the exhaust function of the gas duct during the pouring stage.

[0034] In this embodiment, the arrangement of the main exhaust channel 1 and the auxiliary exhaust channel 5 changes the drawback of the single exhaust path of the traditional exhaust structure, and forms a graded exhaust. The auxiliary exhaust channel 5 is spirally distributed around the main exhaust channel 1. In the early stage of pouring, the auxiliary exhaust channel 5 establishes a low-resistance exhaust channel in advance to guide the gas to form a swirl and accelerate the discharge. When the gas pressure is high during the peak period of filling, the main exhaust channel 1 is opened and works together with the auxiliary exhaust channel 5 to achieve efficient exhaust and reduce turbulence.

[0035] The secondary exhaust duct 5 is provided with a connecting airway 7 which is radially connected to the main exhaust duct 1, and the diameter of the connecting airway 7 is 1 / 5-1 / 3 of the diameter of the main exhaust duct 1. The connecting airway 7 makes the main exhaust duct 1 and the secondary exhaust duct 5 both independent and interconnected, forming a bionic exhaust system similar to "trunk-branch". At the same time, the connecting airway 7 which is radially connected to the main exhaust duct 1 is provided on the secondary exhaust duct 5 to realize the gas exchange between the main exhaust duct 1 and the secondary exhaust duct 5. In the early stage of pouring, a small amount of gas enters the main exhaust duct 1 from the secondary exhaust duct 5 through the connecting airway 7. When the main exhaust duct 1 is opened, the secondary exhaust duct 5 guides the gas to accelerate into the main exhaust duct 1, automatically equalizes the pressure, and avoids local high pressure in the airway. When the air pressure in the main exhaust duct 1 increases suddenly, the gas is rebounded to the secondary exhaust duct 5 through the connecting airway 7 for spiral buffering, and the swirl in the secondary exhaust duct 5 and the airflow in the main exhaust duct 1 form a counter-energy dissipation.

[0036] The inner walls of the main exhaust duct 1 and the auxiliary exhaust duct 5 are provided with a ceramic coating. The ceramic coating has excellent properties such as high temperature resistance, wear resistance, and corrosion resistance, which can protect the inner wall, reduce the scouring and erosion of the inner wall by the metal liquid, and extend the service life of the exhaust duct. Its smooth surface can also reduce the resistance of gas flow and improve the exhaust efficiency.

[0037] The exhaust assembly 3 includes an exhaust plug 31, the top of the exhaust plug 31 is a cylindrical structure, the bottom of the exhaust plug 31 is an inverted frustum structure, and the outer circumferential surface of the exhaust plug 31 is provided with a plurality of exhaust grooves 32, and the plurality of exhaust grooves 32 are distributed along the circumferential direction of the exhaust plug 31, and each exhaust groove 32 is only connected to the upper end surface of the exhaust plug 31; the outlet end of the main exhaust duct 1 is provided with a reducer 12 abutting against the outer circumferential surface of the exhaust plug 31; the upper end surface of the exhaust plug 31 is connected to a clamping spring 33, and the top end of the clamping spring 33 is connected to a clamping plate 34, and the clamping plate 34 is a circular plate, and a clamping rod 35 connected to the outer surface of the mold 2 is provided at the bottom of the clamping plate 34, and a plurality of clamping rods 35 are provided, and the plurality of clamping rods 35 are distributed along the circumferential direction of the clamping plate 34, and the clamping rod 35 is parallel to the axis of the main exhaust duct 1. An annular groove 21 is provided on the outer surface of the mold 2, and the annular groove 21 is coaxially arranged with the clamping plate 34. The inner wall of the annular groove 21 has an internal thread, and the inner side of the clamping rod 35 has an external thread that matches the outer wall of the annular groove 21. The clamping rod 35 is threadedly connected to the annular groove 21.

[0038] In this embodiment, when the gas pressure in the main exhaust passage 1 is relatively high, the gas presses against the exhaust plug 31, the compression spring 33 is compressed and deformed, the exhaust plug 31 moves upward, and the outer peripheral surface of the truncated cone structure at the bottom of the exhaust plug 31 is separated from the diameter reducing portion 12, forming an annular gap, connecting the exhaust groove 32 and the main exhaust passage 1, so that the gas can be smoothly discharged from the exhaust groove 32. When the gas pressure decreases, the compression spring is reset, and the annular gap is closed to prevent the molten metal from flowing back and leaking.

[0039] The present embodiment is a venting structure of a casting mold. The specific position of the venting structure on the mold 2 is determined by methods in the prior art, such as by the end of the molten metal flow or in combination with the overflow groove position, etc. This embodiment will not discuss this further.

[0040] Working process: After the casting operation is started, before the molten metal flows into the cavity on a large scale, the gas pressure in the cavity is still low, the opening and closing assembly 4 at the inlet end of the main exhaust channel 1 is in a sealed state, and the auxiliary exhaust channel 5 begins to play a role. The auxiliary exhaust channel 5 is distributed in a spiral shape around the main exhaust channel 1, so that the gas in the cavity can enter smoothly, form a vortex, and be discharged quickly, so as to establish a low-resistance exhaust channel in advance.

[0041] When pouring enters the peak period, the molten metal fills the mold at a high speed, and the gas pressure in the mold cavity rises rapidly. When the gas pressure reaches a certain level, it acts on the structure of the semi-enclosed area of ​​the middle fracture 421 of the sealing disc 42, causing it to tilt upward, pushing away the elastic sheet 41 abutting against it, and the main exhaust duct 1 opens. The tilting degree of the semi-enclosed area structure is automatically adjusted with the gas pressure, and a large amount of gas can quickly enter the main exhaust duct 1. At the same time, part of the gas in the auxiliary exhaust duct 5 passes through the connecting airway 7 radially connected to the main exhaust duct 1. On the basis that a small amount of gas has entered the main exhaust duct 1 through this channel at the beginning of pouring, it is further accelerated to flow into the main exhaust duct 1, realizing automatic pressure equalization and avoiding local high pressure in the airway. If the air pressure in the main exhaust duct 1 increases suddenly, the gas will also rebound to the auxiliary exhaust duct 5 through the connecting airway 7, and the spiral structure of the auxiliary exhaust duct 5 will be used for buffering, and its swirl will counteract the airflow of the main exhaust duct 1 to dissipate energy.

[0042] When the gas pressure in the main exhaust duct 1 is relatively high, the gas pushes against the exhaust plug 31, the compression spring 33 is deformed under pressure, the exhaust plug 31 moves upward, and the outer peripheral surface of the bottom frustum structure is separated from the reducing portion 12 at the outlet end of the main exhaust duct 1, forming an annular gap, connecting the exhaust groove 32 and the main exhaust duct 1, and the gas is discharged smoothly from the exhaust groove 32.

[0043] After pouring, the air pressure in the cavity decreases, and the sealing disc 42 returns to its original state under the action of its own elasticity and the change of surrounding air pressure, and closely cooperates with the elastic sheet 41 to achieve sealing, preventing the molten metal from flowing back to the main exhaust channel 1. At the exhaust component 3, the compression spring is reset, the exhaust plug 31 moves down, and the annular gap is closed, ensuring the sealing performance of the exhaust plug 31 and the reducer 12, and preventing the molten metal from flowing back and leaking. Trace gas is discharged from the secondary exhaust channel 5.

[0044] Embodiment 2: Reference Figure 4 Embodiment 2 discloses a casting mold exhaust structure. The difference between Embodiment 2 and Embodiment 1 is that a plurality of arc-shaped recessed portions 13 are provided on the inner wall of the main exhaust duct 1 .

[0045] The arc-shaped recessed portion 13 can change the flow path of the gas in the main exhaust duct 1, increase the disturbance of the gas flow, make the gas more likely to contact the inner wall of the main exhaust duct 1 during the flow process, and promote the impurities in the gas (such as small particles formed by the splash of the molten metal, etc.) to adhere to the main exhaust duct 1. The arc-shaped recessed portion 13 changes the roughness and geometric shape of the inner wall of the main exhaust duct 1, and increases the surface roughness and surface area. When the molten metal contacts the surface with the arc-shaped recessed portion 13, due to the effect of surface tension, the molten metal will preferentially fill the pit, and a thin air film will be formed between the molten metal and the inner wall of the main exhaust duct 1, which can effectively isolate the direct contact between the molten metal and the inner wall of the main exhaust duct 1, and reduce the adhesion of the molten metal to the inner wall of the main exhaust duct 1.

[0046] Even if the molten metal adheres to the inner wall of the main exhaust duct 1, the arc-shaped recessed portion 13 changes the flow path of the gas in the main exhaust duct 1, increases the disturbance of the gas flow, and makes it easier for the gas to contact the inner wall of the main exhaust duct 1 during the flow, thereby enabling the gas to drive the molten metal and impurities in the gas (such as small particles formed by the splashing of the molten metal) to adhere to the arc-shaped recessed portion 13, thereby reducing the possibility of impurities entering the exhaust component 3 or the auxiliary exhaust duct 5 and preventing the exhaust duct from being blocked.

[0047] At the same time, the arc-shaped recessed portion 13 also helps to disperse the pressure of the gas flow, so that the gas flows more evenly in the main exhaust duct 1, thereby improving the exhaust effect and reducing the generation of turbulence.

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A casting mold exhaust structure, comprising a main exhaust duct (1), the main exhaust duct (1) being connected to a mold cavity of a mold (2), characterized in that: An exhaust assembly (3) is provided at the outlet end of the main exhaust duct (1), and an opening and closing assembly (4) is provided at the inlet end of the main exhaust duct (1); The opening and closing assembly (4) comprises an elastic sheet (41) and a sealing disc (42), the two sides of the elastic sheet (41) abut against the inner wall of the main exhaust passage (1), the elastic sheet (41) is bent downward to abut against the sealing disc (42), the outer periphery of the sealing disc (42) abuts against the inner wall of the main exhaust passage (1), a first separation fracture (421) is provided in the middle of the sealing disc (42), and the structure of the sealing disc (42) in the semi-enclosed area of ​​the fracture (421) can have a tendency to warp upward under the action of air pressure; The mold (2) is provided with a secondary exhaust channel (5), the secondary exhaust channel (5) is communicated with the mold cavity of the mold (2), the secondary exhaust channel (5) is distributed in a spiral shape around the main exhaust channel (1), the inner diameter of the secondary exhaust channel (5) is smaller than that of the main exhaust channel (1), and the outlet end and the inlet end of the secondary exhaust channel (5) are both provided with a vent plug (6), and the vent plug (6) is provided with a plurality of vent holes with a diameter less than 0.2 mm.

2. A casting mold exhaust structure according to claim 1, characterized in that: The axis of the inlet end of the auxiliary exhaust channel (5) forms an angle of 15°-25° with the surface of the cavity, and the axis of the outlet end of the auxiliary exhaust channel (5) forms an angle of 15°-25° with the outer surface of the mold (2).

3. A casting mold exhaust structure according to claim 1, characterized in that: The secondary exhaust duct (5) is provided with a communication duct (7) which is radially connected to the main exhaust duct (1).

4. A casting mold exhaust structure according to claim 1, characterized in that: The exhaust assembly (3) comprises an exhaust plug (31), the top of the exhaust plug (31) is a cylindrical structure, the bottom of the exhaust plug (31) is an inverted truncated cone structure, the outer peripheral surface of the exhaust plug (31) is provided with a plurality of exhaust grooves (32), the plurality of exhaust grooves (32) are distributed along the circumferential direction of the exhaust plug (31), and each exhaust groove (32) is only connected to the upper end surface of the exhaust plug (31); the outlet end of the main exhaust passage (1) is provided with a diameter reducing portion (12) abutting against the outer peripheral surface of the exhaust plug (31); The upper end surface of the exhaust plug (31) is connected to a compression spring (33), the top end of the compression spring (33) is connected to a compression plate (34), and the bottom of the compression plate (34) is provided with a compression rod (35) connected to the outer surface of the mold (2), and the compression rod (35) is parallel to the axis of the main exhaust duct (1).

5. A casting mold exhaust structure according to claim 4, characterized in that: The clamping plate (34) is a circular plate, and a plurality of clamping rods (35) are provided. The plurality of clamping rods (35) are distributed along the circumferential direction of the clamping plate (34).

6. A casting mold exhaust structure according to claim 5, characterized in that: An annular groove (21) is provided on the outer surface of the mold (2). The annular groove (21) is coaxially arranged with the clamping plate (34). An inner wall of the annular groove (21) is provided with an internal thread. An inner side of the clamping rod (35) is provided with an external thread matching the outer wall of the annular groove (21). The clamping rod (35) is threadedly connected to the annular groove (21).

7. A casting mold exhaust structure according to claim 1, characterized in that: The inner wall of the outlet end of the main exhaust passage (1) is provided with a circle of protrusions (11), and the top of the elastic sheet (41) abuts against the protrusions (11).

8. A casting mold exhaust structure according to claim 1, characterized in that: The inner wall of the main exhaust passage (1) is provided with a plurality of arc-shaped recessed portions (13).

9. A casting mold exhaust structure according to claim 1, characterized in that: The melting points of the elastic sheet (41) and the sealing disc (42) are higher than 800°C.

10. A casting mold exhaust structure according to claim 1, characterized in that: The inner walls of the main exhaust passage (1) and the auxiliary exhaust passage (5) are provided with a ceramic coating.

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