Vacuum valve

Abstract

The present invention relates to the technical field of vacuum valves, and specifically discloses a vacuum valve, which includes a valve seat. The valve seat has a receiving space, and the receiving space is provided with a first connection part, a second connection part, a third connection part and two buffer channels. A core pulling seat is arranged on the valve seat, a guiding part is arranged on the core pulling seat, a valve core is slidably arranged on the guiding part, the valve core has a bearing groove, a pressure maintaining mechanism is arranged on the guiding part, and a mounting bracket is arranged on the pressure maintaining mechanism; for the vacuum valve of the present invention, when injecting molten metal into the mold, the initial molten metal will first impact the bearing groove on the valve core, and the inner wall contour of the bearing groove guides the molten metal to flow outward and impact the just-entering molten metal, so as to reduce the amount of molten metal surging towards the sealing surface. And the molten metal will flow through the first connection part to the buffer channel, further reducing the amount of molten metal surging towards the sealing surface. The initial molten metal will be blocked by the sealing surface to prevent the initial molten metal from directly entering the air extraction channel and avoiding blockage of the air extraction channel.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum valves, and in particular to vacuum valves. Background Art

[0002] During the die-casting process of metal parts, the air inside the mold cavity will cause poor die-casting filling, and eventually cause pores in the die-casting after processing. In order to avoid pores in die-cast products, it is usually necessary to increase the exhaust at the end of the mold filling. The more commonly used exhaust method is to use a vacuum pump to extract the air in the mold to exhaust, and use a vacuum valve between the mold and the vacuum pump to prevent the molten metal from entering the vacuum tank of the vacuum pump.

[0003] However, there is a problem with the existing vacuum valve during use. When the vacuum valve is evacuated, the vacuum valve remains in an open state, that is, an exhaust channel for gas to pass through is formed between the valve body and the valve core, and the closing of the valve core depends on the impact of the molten metal. Although the impact of the molten metal is sufficient to push the valve core to completely seal the valve body channel, when the molten metal initially impacts the valve core, this initial molten metal is equivalent to moving synchronously with the valve core. A small amount of this molten metal may flow into the exhaust channel when the valve core has not completely closed the exhaust channel. After the molten metal is cooled, the exhaust channel will be blocked, affecting the normal use of the vacuum valve. Summary of the invention

[0004] The present invention provides a vacuum valve, aiming to solve the problem in the related art that when molten metal initially impacts a valve core, the initial molten metal may flow into an exhaust channel when the valve core does not completely close the exhaust channel.

[0005] The vacuum valve of the present invention comprises a valve seat, the valve seat has a storage space that can be communicated with the exhaust port of the die-casting mold, the storage space can be communicated with the exhaust port at the filling end of the die-casting mold, the storage space has a first connection part, a second connection part and a third connection part that are connected in sequence, and the storage space also has two buffer channels that are respectively connected to both sides of the first connection part, and each of the buffer channels is connected to the third connection part;

[0006] A core-pulling seat, arranged on the valve seat, having an air-pumping passage communicating with the accommodating space and an air-pumping hole communicating with the air-pumping passage;

[0007] A guide member, arranged on the core-pulling seat;

[0008] A valve core is slidably arranged on the guide member, the valve core has a bearing groove and a sealing boss placed in the accommodating space, the sealing boss has a closing surface, the gap between the closing surface and the side wall of the third connecting part is less than 0.05 mm, and the sealing boss can move to block the air extraction channel;

[0009] A pressure-holding mechanism is provided on the guiding member and connected to the valve core, for providing pressure to maintain the state of the valve core;

[0010] An installation bracket is provided on the pressure-holding mechanism.

[0011] Preferably, the valve seat includes a fixed module and a moving module that are snap-fitted to each other. Both the snap-fitting surfaces of the fixed module and the moving module have mating grooves that are snap-fitted to each other. The two mating grooves have the same shape profile. The accommodating space is jointly formed by the two mating grooves. The moving module has an installation through-hole that communicates with the accommodating space. The installation through-hole is inserted into the core-pulling seat, and each of the buffer channels is serpentine.

[0012] Preferably, the pressure-holding mechanism has a seat plate. The seat plate has a first sealing ring. A seat body is fixedly provided on the seat plate. The seat body is provided with a pressure-holding air hole and a reset air hole. The pressure-holding air hole communicates with an external constant air pressure source. A sliding core is slidably provided on the seat plate. The sliding core has a first sliding portion connected to the valve core, a boss portion connected to the first sliding portion, and a second sliding portion connected to the boss portion. There is a gap between the boss portion and the inner wall of the seat body. The boss portion abuts against the first sealing ring. The diameter of the first sliding portion is smaller than that of the second sliding portion. The diameter of the boss portion is larger than that of the second sliding portion. A pressure-holding cavity communicating with the pressure-holding air hole is formed among the sliding core, the seat plate, the first sealing ring, and the seat body. A reset cavity communicating with the reset air hole is formed between the sliding core and the seat body.

[0013] Preferably, the seat plate is further provided with a sealing groove and a dust-proof groove. A second sealing ring is snap-fitted in the sealing groove, and the second sealing ring abuts against the inner wall of the seat body. A dust-proof ring is snap-fitted in the dust-proof groove, and the dust-proof ring abuts against the outer wall of the sliding core.

[0014] Preferably, the installation bracket includes a bracket. A hydraulic cylinder is fixedly installed on the bracket. A movable bracket is fixedly provided at the movable end of the hydraulic cylinder. The movable bracket has an installation groove. A support member is placed in the installation groove. The seat plate and the seat body are both disposed between the installation groove and the support member. The support member includes two cushion plates.

[0015] Preferably, it further includes two disassembly and assembly mechanisms for driving the two cushion plates to move respectively, so as to realize the actions of the two cushion plates being inserted into or disengaged from the installation groove.

[0016] Preferably, each of the disassembly and assembly mechanisms includes two transmission structures respectively provided on both sides of the cushion plate, a linkage structure connected between the two transmission structures, and a driving structure installed on the movable bracket. The driving structure is used to provide power to drive one of the transmission structures to operate. The linkage structure can transmit power so that the two transmission structures operate simultaneously. The operation of the two transmission structures can respectively drive both sides of the cushion plate to drive the cushion plate to move.

[0017] Preferably, each of the transmission structures includes a connection block fixed on the movable frame and a rack section opened on the side of the backing plate. A moving rod is threadedly connected to the connection block. A transmission hole is opened on the moving rod. A transmission rod is slidably connected in the transmission hole with a single degree of freedom. A support plate is fixed on the outside of the transmission rod. A first elastic member is fixed between the support plate and the moving rod. A toothed ring is rotatably connected to the support plate. A second elastic member is fixed between the toothed ring and the transmission rod. The toothed ring meshes with the rack section.

[0018] Preferably, the linkage structure includes two limiting plates respectively fixed on the two moving rods. The same connecting plate is rotatably provided on the two limiting plates. A rotating shaft is rotatably provided on the connecting plate. A first gear and a first sprocket are fixed on the rotating shaft. The teeth of the first gear mesh with a second gear. The teeth of the first sprocket engage with a chain. The chain engages with a second sprocket. The second gear and the second sprocket are respectively fixed on the two moving rods. The first gear and the second gear are the same in size and shape. The first sprocket and the second sprocket are the same in size and shape.

[0019] Preferably, the driving structure includes a driving motor fixedly installed on the movable frame. A tooth column is fixed on the output end of the driving motor. A third gear meshes with the tooth column, and the third gear can slide on the tooth column. The third gear is fixedly connected to one of the moving rods.

[0020] The beneficial effects of the present invention are as follows:

[0021] When injecting molten metal into the mold, the initial molten metal will first impact the bearing groove on the valve core. The inner wall contour of the bearing groove guides the molten metal to flow outward and impact the newly entered molten metal, so as to reduce the amount of molten metal surging towards the sealing surface. And the molten metal will flow through the first connecting portion to the buffer channel, further reducing the amount of molten metal surging towards the sealing surface. In addition, since the gap between the sealing surface and the side wall of the third connecting portion is less than 0.05 mm, the flow of molten metal from the second connecting portion to the third connecting portion can be blocked. The initial molten metal will be blocked to prevent the initial molten metal from directly entering the air extraction channel. At the same time, the valve core moves under the impact force, so that the sealing boss moves to keep the air extraction channel closed, improving the ability of the valve core to completely close the air extraction channel, effectively avoiding the initial part of the molten metal from entering the air extraction channel, preventing the molten metal from causing blockage of the air extraction channel, and further avoiding affecting the normal use of the vacuum valve. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the first embodiment of the present invention.

[0023] Figure 2 is a three-dimensional cross-sectional view of the first embodiment of the present invention.

[0024] Figure 3 It is a three-dimensional sectional view of the valve seat of the first embodiment in the present invention.

[0025] Figure 4 It is a structural schematic diagram of the moving module of the first embodiment in the present invention.

[0026] Figure 5 It is a three-dimensional sectional view of the core-pulling seat, guide member, valve core and pressure-holding mechanism of the first embodiment in the present invention.

[0027] Figure 6 It is a sectional view of the seat plate of the first embodiment in the present invention.

[0028] Figure 7 It is a sectional view of the seat body of the first embodiment in the present invention.

[0029] Figure 8 It is a structural schematic diagram of the sliding core of the first embodiment in the present invention.

[0030] Figure 9 It is a structural schematic diagram of the mounting bracket of the first embodiment in the present invention.

[0031] Figure 10 It is a structural schematic diagram of the second embodiment in the present invention.

[0032] Figure 11 It is a structural schematic diagram of the movable frame, backing plate and disassembly and assembly mechanism of the second embodiment in the present invention.

[0033] Figure 12 It is a structural schematic diagram of the disassembly and assembly mechanism of the second embodiment in the present invention.

[0034] Figure 13 It is a three-dimensional sectional view of the transmission rod and the toothed ring of the second embodiment in the present invention.

[0035] Figure 14 It is a sectional view of the linkage structure of the second embodiment in the present invention.

[0036] Reference numerals:

[0037] 10. Valve seat; 11. Fixed module; 12. Moving module; 121. Installation through-hole; 13. Accommodating space; 131. Main runner; 132. Movable runner; 1321. First connection part; 1322. Second connection part; 1323. Third connection part; 1324. Buffer runner; 133. Installation runner; 20. Core-pulling seat; 21. Air extraction channel; 211. First mating inclined surface; 22. Air extraction hole; 30. Guide part; 31. Sleeve; 32. Plug; 321. Guide hole; 40. Valve core; 41. Valve stem; 42. Valve head; 421. Bearing groove; 422. Sealing boss; 4221. Sealing surface; 4222. Second mating inclined surface; 50. Pressure-holding mechanism; 51. Seat plate; 511. Annular inclined groove; 512. First sealing ring; 513. Sealing groove; 514. Dust-proof groove; 515. Second sealing ring; 516. Dust-proof ring; 52. Seat body; 521. Pressure-holding air hole; 522. Reset air hole; 523. First stepped groove; 524. Second stepped groove; 53. Sliding core; 531. First sliding part; 532. Boss part; 533. Second sliding part; 54. Pressure-holding cavity; 55. Reset cavity; 60. Installation frame; 61. Bracket; 62. Hydraulic cylinder; 63. Movable frame; 631. Installation groove; 64. Support part; 641. Base plate; 70. Disassembly and assembly mechanism; 71. Transmission structure; 711. Connection block; 712. Moving rod; 713. Transmission rod; 714. Support plate; 715. First elastic part; 716. Tooth ring; 717. Second elastic part; 718. Rack segment; 72. Linkage structure; 721. Limiting plate; 722. Connection plate; 723. Rotating shaft; 724. First gear; 725. First sprocket; 726. Second gear; 727. Chain; 728. Second sprocket; 73. Driving structure; 731. Driving motor; 732. Tooth column; 733. Third gear. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] As Figures 1 to 9As shown in the figure, this is the first embodiment of the vacuum valve of the present invention, which includes a valve seat 10 for connecting with a mold. The valve seat 10 has an accommodation space 13 capable of communicating with the exhaust port of the mold. A core-pulling seat 20 is inserted into the valve seat 10. The core-pulling seat 20 has an air extraction channel 21 communicating with the accommodation space 13. A guiding member 30 is connected to the core-pulling seat 20. A valve core 40 penetrates through the air extraction channel 21 and is slidably connected to the guiding member 30. The movement of the valve core 40 can open and close the air extraction channel 21. A pressure-holding mechanism 50 is connected to the guiding member 30 for maintaining the state of the valve core 40. An installation bracket 60 is connected to the pressure-holding mechanism 50 to support the entire vacuum valve.

[0040] Refer to Figures 1 to 4 As shown in the figure, the valve seat 10 includes a fixed module 11 and a movable module 12 that are snap-fitted with each other. The fixed module 11 is fixedly installed on the fixed mold of the die-casting mold, and the movable module 12 is fixedly installed on the movable mold of the die-casting mold. As the fixed mold and the movable mold in the mold open and close, the movable module 12 can move along with the movable mold. The mating surfaces of the fixed module 11 and the movable module 12 both have mating grooves that are snap-fitted with each other. The two mating grooves have the same shape profile, and the two mating grooves together enclose the accommodation space 13. The accommodation space 13 communicates with the exhaust port at the filling end of the die-casting mold. The movable module 12 also has an installation through-hole 121 communicating with the accommodation space 13, and the installation through-hole 121 is for the core-pulling seat 20 to be inserted.

[0041] It should be specifically noted that, continuing to refer to Figure 3 and Figure 4 As shown in the figure, the accommodation space 13 has a main runner 131, a movable runner 132 continuous with the main runner 131, and an installation runner 133 continuous with the movable runner 132. The port of the main runner 131 communicates with the exhaust port at the filling end of the die-casting mold. The end of the installation runner 133 communicates with the installation through-hole 121. The movable runner 132 has a first connection portion 1321 communicating with the main runner 131, a second connection portion 1322 continuous with the first connection portion 1321, a third connection portion 1323 continuous with the second connection portion 1322, and two buffer runners 1324 respectively continuous on both sides of the first connection portion 1321. And the third connection portion 1323 is continuous with the installation runner 133. Each buffer runner 1324 is serpentine, and both ends of each buffer runner 1324 are respectively continuous with the first connection portion 1321 and the third connection portion 1323.

[0042] Refer to Figure 1 、 Figure 2 and Figure 5As shown, the core-pulling seat 20 is inserted into the installation through-hole 121 and the installation channel 133. The core-pulling seat 20 has an air extraction channel 21 and air extraction holes 22 communicating with the air extraction channel 21. The air extraction channel 21 has a first mating inclined surface 211 continuous with the third connecting portion 1323. The air extraction holes 22 are connected to an external vacuum pump. Starting the external vacuum pump can extract air from the cavity of the mold through the air extraction holes 22, the air extraction channel 21, and the accommodation space 13.

[0043] Refer to Figure 1 , Figure 2 and Figure 5 As shown in the figures, the guiding member 30 is used to connect the core-pulling seat 20 and the pressure-holding mechanism 50. The guiding member 30 includes a sleeve 31. The sleeve 31 is fixedly connected between the core-pulling seat 20 and the pressure-holding mechanism 50. A plug 32 is fixedly connected to the sleeve 31, and the plug 32 extends into the air extraction channel 21 on the core-pulling seat 20. A guiding hole 321 is formed in the plug 32, and the valve core 40 is slidably connected in the guiding hole 321.

[0044] Refer to Figure 2 and Figure 5 As shown in the figures, the valve core 40 has a valve stem 41 and a valve head 42 connected to the valve stem 41. The valve stem 41 is restricted to slide in the guiding hole 321. The movement of the valve stem 41 is guided by the restriction of the guiding hole 321 to ensure the stability of the valve core 40. The valve head 42 is placed in the accommodation space 13. Specifically, the valve head 42 has a bearing groove 421 and a sealing boss 422. The bearing groove 421 is conical and can directly bear the impact of the molten metal. The sealing boss 422 has a sealing surface 4221 and a second mating inclined surface 4222. The gap between the sealing surface 4221 and the side wall of the third connecting portion 1323 is less than 0.05 mm. It should be noted that the molten metal cannot enter a gap less than 0.05 mm, which can cut off the flow of the molten metal from the second connecting portion 1322 to the third connecting portion 1323. The second mating inclined surface 4222 is parallel to the first mating inclined surface 211. The movement of the sealing boss 422 can make the second mating inclined surface 4222 fit on the first mating inclined surface 211.

[0045] It should be noted that starting the external vacuum pump can extract the air in the mold successively along the main runner 131, the first connecting portion 1321 on the movable runner 132, the buffer runner 1324, the third connecting portion 1323 on the movable runner 132, the gap between the valve core 40 and the air extraction channel 21, and the air extraction holes 22; after the molten metal fills the mold, it will be discharged through the exhaust port at the filling end of the mold and enter the accommodating space 13. At the same time, the impact force of the molten metal will push against the bearing groove 421 on the valve head 42 to force the valve core 40 to move. The movement of the valve head 42 can make the sealing surface 4221 away from the third connecting portion 1323 and make the second mating inclined surface 4222 fit the first mating inclined surface 211 on the air extraction channel 21 to seal the air extraction holes 22, and the molten metal fills the accommodating space 13. In addition, the bearing groove 421 of the valve head 42 will expand thermally under the influence of the heat of the molten metal. The thermally expanded valve head 42 deforms and expands outward, making the second mating inclined surface 4222 on the valve head 42 fit more tightly with the first mating inclined surface 211 to prevent the molten metal from entering the air extraction channel 21.

[0046] Reference Figure 1 、 Figure 2 、 Figures 5 to 8 As shown in the figure, the pressure maintaining mechanism 50 includes a seat plate 51. The seat plate 51 is fixedly connected to the sleeve 31. The seat plate 51 has an annular inclined groove 511. A first sealing ring 512 is sleeved in the annular inclined groove 511. A seat body 52 is fixedly connected to the seat plate 51. The seat body 52 is provided with a pressure maintaining air hole 521, a reset air hole 522, a first stepped groove 523 communicated with the pressure maintaining air hole 521, and a second stepped groove 524 communicated with the reset air hole 522. The pressure maintaining air hole 521 is communicated with an external constant air pressure source. A sliding hole is provided on the seat plate 51. A sliding core 53 is slidably connected in the sliding hole on the seat plate 51. The sliding core 53 has a first sliding portion 531 detachably connected to the valve stem 41, a boss portion 532 connected to the first sliding portion 531, and a second sliding portion 533 connected to the boss portion 532. It should be noted that there is a gap between the boss portion 532 and the inner wall of the first stepped groove 523. The top of the boss portion 532 abuts against the first sealing ring 512. The diameter of the first sliding portion 531 is smaller than that of the second sliding portion 533. The diameter of the boss portion 532 is larger than that of the second sliding portion 533. A pressure maintaining cavity 54 is formed among the sliding core 53, the seat plate 51, the first sealing ring 512, and the inner wall of the first stepped groove 523 on the seat body 52. A reset cavity 55 is formed between the sliding core 53 and the inner wall of the second stepped groove 524 on the seat body 52.

[0047] Continue to refer to Figures 5 to 7As shown, a sealing groove 513 and a dust-proof groove 514 are also formed in the seat plate 51. A second sealing ring 515 is clamped in the sealing groove 513. The second sealing ring 515 is made of elastic rubber material. The second sealing ring 515 abuts against the inner wall of the first-step groove 523. The second sealing ring 515 can block the gap between the inner wall of the first-step groove 523 and the seat plate 51 to prevent the air in the pressure-holding cavity 54 from leaking along the gap between the inner wall of the first-step groove 523 and the seat plate 51. A dust-proof ring 516 is clamped in the dust-proof groove 514. The dust-proof ring 516 is made of elastic rubber material. The dust-proof ring 516 abuts against the outer wall of the sliding core 53. The dust-proof ring 516 can block the gap between the sliding core 53 and the seat plate 51 to prevent impurities from entering the pressure-holding cavity 54 along the gap between the sliding core 53 and the seat plate 51. In addition, the air in the pressure-holding cavity 54 can leak along the gap between the dust-proof ring 516 and the sliding core 53.

[0048] In this embodiment, the first sliding portion 531 extends into the inside of the sleeve 31. A hook groove is formed in the first sliding portion 531, and a hanging head is provided on the valve stem 41 so that the hanging head can be placed in the hook groove to achieve the detachable connection between the first sliding portion 531 and the sliding core 53. It should be noted that the central axes of the sliding core 53, the valve core 40, the sleeve 31, the plug 32, the air extraction channel 21, and the main flow channel 131 are collinear.

[0049] Refer to Figure 1 、 Figure 2 and Figure 9 As shown in, the mounting frame 60 includes a bracket 61. A hydraulic cylinder 62 is fixedly mounted on the bracket 61. The movable end of the hydraulic cylinder 62 is fixedly connected with a movable frame 63. An installation groove 631 is provided on the movable frame 63. A support member 64 is placed in the installation groove 631. In this embodiment, the support member 64 is made of a plate-shaped steel plate. Both the seat plate 51 and the seat body 52 are placed between the installation groove 631 and the support member 64. After the support member 64 is manually pulled out, the space in the installation groove 631 can be vacated, and then the pressure-holding mechanism 50 can be controlled to move in the installation groove 631, which is convenient for disassembling and assembling the vacuum valve. Controlling the hydraulic cylinder 62 to extend can drive the pressure-holding mechanism 50 towards the direction of the valve seat 10 through the bracket 61, the movable frame 63, and the support member 64. At the same time, through the transmission of the guiding member 30, the connection strength between the core-pulling seat 20 and the valve seat 10 is also enhanced.

[0050] In use, an external constant air pressure source introduces a constant air pressure into the pressure-holding cavity 54 through the pressure-holding air hole 521, and introduces a primary gas through the reset air hole 522 to push the sliding core 53 to move. The movement of the sliding core 53 causes the top of the boss portion 532 to abut against the first sealing ring 512, and at the same time closes the communication between the first sliding portion 531 and the gas in the pressure-holding cavity 54. At this time, since the diameter after the enclosure of the boss portion 532 and the first sealing ring 512 is larger than the diameter of the second sliding portion 533, the gas pressure in the pressure-holding cavity 54 pushes the sliding core 53 to move towards the valve seat 10, causing the boss portion 532 to further press against the first sealing ring 512, maintaining the pressure of the sliding core 53 towards the valve seat 10 direction. And due to the air leakage through the gap between the dust-proof ring 516 and the sliding core 53, a pressure difference can be generated above and below the first sealing ring 512, which can adsorb the first sealing ring 512 between the boss portion 532 and the seat plate 51 to block the gap between the boss portion 532 and the seat plate 51. At the same time, the movement of the sliding core 53 drives the movement of the valve core 40, causing the sealing surface 4221 on the valve core 40 to tend to the side wall of the third connecting portion 1323, so that the gap between the sealing surface 4221 and the third connecting portion 1323 is less than 0.05 mm. Since the molten metal cannot enter a gap less than 0.05 mm, the purpose of disconnecting the flow of molten metal from the second connecting portion 1322 to the third connecting portion 1323 is achieved, while the first connecting portion 1321, the buffer channel 1324, the third connecting portion 1323 on the active channel 132, the gap between the valve core 40 and the air extraction channel 21, and the air extraction hole 22 on the main channel 131 and the active channel 132 are in a through state.

[0051] Then starting the external vacuum pump can extract the air in the mold successively along the main channel 131, the first connecting portion 1321 on the active channel 132, the buffer channel 1324, the third connecting portion 1323 on the active channel 132, the gap between the valve core 40 and the air extraction channel 21, and the air extraction hole 22. Since the sliding core 53 maintains the pressure towards the valve seat 10 direction, the valve core 40 will not be pulled back by the low-pressure air flow generated by the vacuum extraction to close the passage, ensuring the efficiency of vacuum extraction.

[0052] Then, metal liquid is injected into the mold. Since the gap between the sealing surface 4221 and the side wall of the third connecting portion 1323 is less than 0.05 mm, the flow of the metal liquid from the second connecting portion 1322 to the third connecting portion 1323 is blocked. When the metal liquid enters the accommodating space 13, the initial metal liquid will first impact the bearing groove 421 on the valve core 40 and flow backward along the inner wall contour of the bearing groove 421 to form a reverse impact. The metal liquid of this reverse impact can impact the subsequently entering metal liquid to reduce the amount of metal liquid surging toward the sealing surface 4221. And the metal liquid will flow through the first connecting portion 1321 to the buffer passage 1324 to further reduce the amount of metal liquid surging toward the sealing surface 4221. In addition, due to the blockage of the sealing surface 4221, the initial metal liquid will be blocked to prevent the initial metal liquid from directly entering the air extraction passage 21, improving the ability of the valve core 40 to completely close the air extraction passage 21. At the same time, the valve core 40 moves under the impact force, so that the second mating inclined surface 4222 on the sealing boss 422 fits on the first mating inclined surface 211 on the core pulling seat 20 to keep the air extraction passage 21 closed.

[0053] After the mold is filled with the metal liquid, it will be discharged along the exhaust port at the filling end of the mold and enter the accommodating space 13. At the same time, the impact force of the metal liquid will push the bearing groove 421 on the valve head 42 to force the valve core 40 to move. The movement of the valve head 42 can make the sealing surface 4221 away from the third connecting portion 1323 and make the second mating inclined surface 4222 fit on the first mating inclined surface 211 on the air extraction passage 21 to close the air extraction hole 22, while the metal liquid fills the accommodating space 13.

[0054] In addition, the movement of the valve core 40 drives the movement of the sliding core 53. The sliding core 53 moves to squeeze the gas in the reset cavity 55 and discharges it through the reset air hole 522. The boss portion 532 on the sliding core 53 moves away from the first sealing ring 512. Since the cross-sectional area of the second sliding portion 533 in the pressure maintaining cavity 54 is larger than the cross-sectional area of the first sliding portion 531, the gas pressure in the pressure maintaining cavity 54 quickly pushes the sliding core 53 away from the valve seat 10 to keep the second mating inclined surface 4222 fitting on the first mating inclined surface 211 on the air extraction passage 21 and keep the air extraction hole 22 in a closed state.

[0055] When the die-casting mold is closed again, gas is introduced into the reset air hole 522 once to start the next vacuum pumping, and so on in a cycle.

[0056] In the above embodiment, the extraction and installation of the support member 64 both require manual operations, and the disassembly, assembly and alignment work are very cumbersome. Therefore, a second embodiment is proposed to overcome the above problems;

[0057] As Figures 10 to 14 shown, it is the second embodiment of the vacuum valve of the present invention. The difference from the first embodiment is that the structure of the support member 64 is different. In addition, in the second embodiment, two disassembly and assembly mechanisms 70 are further included.

[0058] In the second embodiment, referring to Figure 11 as shown, the support member 64 includes two backing plates 641, and the two backing plates 641 are inserted between the installation groove 631 and the seat body 52. The two disassembly and assembly mechanisms 70 can drive the two backing plates 641 to move respectively, so as to realize the actions of the two backing plates 641 being inserted into or disengaged from the installation groove 631.

[0059] Referring to Figure 10 and Figure 11 as shown, each disassembly and assembly mechanism 70 includes two transmission structures 71 respectively arranged on both sides of the backing plate 641, a linkage structure 72 connected between the two transmission structures 71, and a driving structure 73 installed on the movable frame 63. The driving structure 73 can provide power to drive one of the transmission structures 71, and the linkage structure 72 can link the two transmission structures 71 together, so that the two transmission structures 71 can respectively drive both sides of the backing plate 641, making the force directions on both sides of the backing plate 641 the same, so as to stably drive the backing plate 641 to move.

[0060] Continuing to refer to Figures 11 to 13 as shown, the transmission structure 71 includes a connection block 711 fixedly installed on the movable frame 63 and a rack section 718 opened on the side of the backing plate 641. A threaded hole is opened on the connection block 711, and a moving rod 712 is threadedly connected in the threaded hole of the connection block 711. A transmission hole is opened on the moving rod 712, and a transmission rod 713 is slidably connected with a single degree of freedom in the transmission hole. In this embodiment, the transmission rod 713 is hexagonal prism-shaped, and the transmission hole is a hexagonal hole matching the transmission rod 713. When the moving rod 712 rotates, it can drive the transmission rod 713 to rotate through the transmission hole on the moving rod 712, and does not affect the sliding of the transmission rod 713 in the transmission hole. A support plate 714 is fixedly connected to the outside of the transmission rod 713, and a first elastic member 715 is fixedly connected between the support plate 714 and the moving rod 712. In this embodiment, the first elastic member 715 is a spring. A toothed ring 716 is rotatably connected to the support plate 714, and a second elastic member 717 is fixedly connected between the toothed ring 716 and the transmission rod 713. In this embodiment, the second elastic member 717 is a torsion spring. The elastic force of the second elastic member 717 is greater than the sum of the gravity of the backing plate 641, the friction force between the seat body 52 and the backing plate 641, and the friction force between the installation groove 631 and the backing plate 641. The teeth of the toothed ring 716 are engaged with the rack section 718, and the linkage structure 72 is connected to the two moving rods 712 and can drive the two moving rods 712 to rotate in opposite directions.

[0061] Continuing to refer to Figures 11 to 14As shown, the linkage structure 72 includes two limiting plates 721 fixedly connected to two moving rods 712 respectively. A same connecting plate 722 is rotatably connected to the two limiting plates 721. When any one of the moving rods 712 moves, it can drive the other moving rod 712 to move synchronously through the two limiting plates 721 and the connecting plate 722. A rotating shaft 723 is rotatably connected to the connecting plate 722 through a bearing. A first gear 724 and a first sprocket 725 are fixedly connected to the rotating shaft 723. The teeth of the first gear 724 mesh with a second gear 726. The teeth of the first sprocket 725 engage with a chain 727, and the chain 727 engages with a second sprocket 728. The second gear 726 and the second sprocket 728 are respectively fixedly connected to the two moving rods 712. It should be noted that the first gear 724 and the second gear 726 are the same in size and shape, and the first sprocket 725 and the second sprocket 728 are the same in size and shape. When any one of the moving rods 712 rotates, it can drive the other moving rod 712 to rotate in the opposite direction through the transmission of the first gear 724, the first sprocket 725, the chain 727, the second gear 726 and the second sprocket 728.

[0062] Continue to refer to Figures 10 to 12 As shown, the driving structure 73 includes a driving motor 731 fixedly installed on the movable frame 63. The output end of the driving motor 731 is fixedly connected with a toothed column 732. A third gear 733 meshes with the toothed column 732, and the third gear 733 can slide on the toothed column 732. The third gear 733 is fixedly connected with one of the moving rods 712.

[0063] When it is necessary to operate the backing plate 641 to disengage from the mounting groove 631, control the driving motor 731 to drive the toothed column 732 to rotate. The rotation of the toothed column 732 drives the third gear 733 to rotate. The rotation of the third gear 733 drives the moving rod 712 connected thereto to rotate. The rotation of the moving rod 712, under the action of the threaded connection between the moving rod 712 and the connecting block 711, causes the moving rod 712 to move away from the valve seat 10. In addition, the movement of the moving rod 712 will drive the third gear 733 to slide on the toothed column 732, and the rotational transmission between the third gear 733 and the toothed column 732 will not be disconnected. Due to the restriction of the rack section 718 on the toothed ring 716, the toothed ring 716, the support plate 714 and the transmission rod 713 cannot follow the moving rod 712 to move away from the valve seat 10. At this time, the first elastic member 715 is stretched and stores energy. The rotation of the moving rod 712 can drive the toothed ring 716 to rotate synchronously through the transmission rod 713 and the second elastic member 717. The rotation of the toothed ring 716 drives the backing plate 641 to move through the engagement between the toothed ring 716 and the rack section 718, so that the backing plate 641 disengages from the mounting groove 631. Once the backing plate 641 disengages from the mounting groove 631, the elastic force of the first elastic member 715 quickly recovers, and at the same time pulls the support plate 714, the transmission rod 713, the toothed ring 716, the second elastic member 717 and the backing plate 641 close to the moving rod 712, thereby realizing the backing plate 641 moving away from the mounting groove 631.

[0064] When the operation backing plate 641 needs to be installed in the installation groove 631, control the driving motor 731 to drive the tooth column 732 to rotate in the reverse direction, and the moving rod 712 moves closer to the valve seat 10, while driving the backing plate 641 closer to the installation groove 631. Since the backing plate 641 cannot move downward under the restriction of the movable frame 63, the power that the moving rod 712 drives the transmission rod 713 to rotate will act on the second elastic member 717, causing the second elastic member 717 to deform and store energy. Once the backing plate 641 moves to directly above the installation groove 631, the second elastic member 717 resumes its original shape, and its elastic force drives the tooth ring 716 to rotate. The rotation of the tooth ring 716 drives the backing plate 641 into the installation groove 631 through the meshing transmission between the tooth ring 716 and the rack segment 718.

[0065] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as a limitation of the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. Vacuum valve, comprising a valve seat (10), wherein the valve seat (10) is provided with a receiving space (13) capable of communicating with the exhaust port of a die-casting mold, characterized in that, The accommodating space (13) is provided with a first connecting portion (1321), a second connecting portion (1322) and a third connecting portion (1323) that are sequentially coherent. The accommodating space (13) is also provided with two buffer channels (1324) that are respectively coherent on both sides of the first connecting portion (1321), and each of the buffer channels (1324) is coherent with the third connecting portion (1323); A core-pulling seat (20) is arranged on the valve seat (10). The core-pulling seat (20) is provided with an air extraction channel (21) that communicates with the accommodating space (13) and an air extraction hole (22) that communicates with the air extraction channel (21). The air extraction channel (21) is provided with a first mating inclined surface (211) that is coherent with the third connecting portion (1323); A guide member (30) is arranged on the core-pulling seat (20); A valve core (40) is slidably arranged on the guide member (30). The valve core (40) is provided with a bearing groove (421) and a sealing boss (422) placed in the accommodating space (13). The sealing boss (422) is provided with a sealing surface (4221) and a second mating inclined surface (4222). The gap between the sealing surface (4221) and the side wall of the third connecting portion (1323) is less than 0.05 mm, so as to cut off the flow of molten metal from the second connecting portion (1322) to the third connecting portion (1323). The second mating inclined surface (4222) is parallel to the first mating inclined surface (211). The movement of the sealing boss (422) can make the second mating inclined surface (4222) fit on the first mating inclined surface (211) to block the air extraction channel (21); A pressure-holding mechanism (50) is arranged on the guide member (30) and is connected to the valve core (40) for providing pressure to maintain the state of the valve core (40); A mounting bracket (60) is arranged on the pressure-holding mechanism (50).

2. The vacuum valve according to claim 1, characterized in that, The valve seat (10) includes a fixed module (11) and a movable module (12) that are buckled with each other. The buckling surfaces of the fixed module (11) and the movable module (12) are both provided with mating grooves that are buckled with each other. The two mating grooves have the same shape profile. The accommodating space (13) is jointly surrounded by the two mating grooves. The movable module (12) is provided with a mounting through hole (121) that communicates with the accommodating space (13). The mounting through hole (121) is inserted into the core-pulling seat (20). Each of the buffer channels (1324) is serpentine.

3. The vacuum valve according to claim 1, characterized in that, The pressure-holding mechanism (50) is provided with a seat plate (51). The seat plate (51) is provided with a first sealing ring (512). A seat body (52) is fixedly arranged on the seat plate (51). A pressure-holding air hole (521) and a reset air hole (522) are formed in the seat body (52). The pressure-holding air hole (521) is communicated with an external constant air pressure source. A sliding core (53) is slidably arranged on the seat plate (51). The sliding core (53) is provided with a first sliding part (531) connected to the valve core (40), a boss part (532) connected to the first sliding part (531), and a second sliding part (533) connected to the boss part (532). There is a gap between the boss part (532) and the inner wall of the seat body (52). The boss part (532) abuts against the first sealing ring (512). The diameter of the first sliding part (531) is smaller than that of the second sliding part (533). The diameter of the boss part (532) is larger than that of the second sliding part (533). A pressure-holding cavity (54) communicated with the pressure-holding air hole (521) is formed among the sliding core (53), the seat plate (51), the first sealing ring (512) and the seat body (52). A reset cavity (55) communicated with the reset air hole (522) is formed between the sliding core (53) and the seat body (52).

4. The vacuum valve according to claim 3, characterized in that, A sealing groove (513) and a dust-proof groove (514) are further formed in the seat plate (51). A second sealing ring (515) is clamped in the sealing groove (513). The second sealing ring (515) abuts against the inner wall of the seat body (52). A dust-proof ring (516) is clamped in the dust-proof groove (514). The dust-proof ring (516) abuts against the outer wall of the sliding core (53).

5. The vacuum valve according to claim 3, characterized in that, The mounting frame (60) includes a bracket (61). A hydraulic cylinder (62) is fixedly mounted on the bracket (61). A movable frame (63) is fixedly arranged at the movable end of the hydraulic cylinder (62). An installation groove (631) is formed in the movable frame (63). A support member (64) is placed in the installation groove (631). Both the seat plate (51) and the seat body (52) are arranged between the installation groove (631) and the support member (64). The support member (64) includes two backing plates (641).

6. The vacuum valve according to claim 5, characterized in that, Two disassembly and assembly mechanisms (70) are further included, which are used to drive the two backing plates (641) to move respectively, so as to realize the actions of the two backing plates (641) being inserted into or separated from the installation groove (631).

7. The vacuum valve according to claim 6, characterized in that, Each of the disassembly and assembly mechanisms (70) includes two transmission structures (71) respectively arranged on both sides of the backing plate (641), a linkage structure (72) connected between the two transmission structures (71), and a driving structure (73) mounted on the movable frame (63). The driving structure (73) is used to provide power to drive one of the transmission structures (71) to operate. The linkage structure (72) can transmit power so that the two transmission structures (71) operate simultaneously. The operation of the two transmission structures (71) can respectively drive both sides of the backing plate (641) to drive the backing plate (641) to move.

8. The vacuum valve according to claim 7, characterized in that, Each of the transmission structures (71) includes a connection block (711) fixed on the movable frame (63) and a rack section (718) opened on the side of the backing plate (641). A moving rod (712) is threadedly connected to the connection block (711). A transmission hole is formed in the moving rod (712). A transmission rod (713) is slidably connected in the transmission hole with a single degree of freedom. A support plate (714) is fixed on the outer part of the transmission rod (713). A first elastic member (715) is fixed between the support plate (714) and the moving rod (712). A gear ring (716) is rotatably connected to the support plate (714). A second elastic member (717) is fixed between the gear ring (716) and the transmission rod (713). The gear ring (716) meshes with the rack section (718).

9. The vacuum valve according to claim 8, characterized in that, The linkage structure (72) includes two limiting plates (721) respectively fixed on the two moving rods (712). The same connecting plate (722) is rotatably provided on the two limiting plates (721). A rotating shaft (723) is rotatably provided on the connecting plate (722). A first gear (724) and a first sprocket (725) are fixed on the rotating shaft (723). The teeth of the first gear (724) mesh with a second gear (726). The teeth of the first sprocket (725) engage with a chain (727). The chain (727) engages with a second sprocket (728). The second gear (726) and the second sprocket (728) are respectively fixed on the two moving rods (712). The first gear (724) and the second gear (726) are the same in size and shape. The first sprocket (725) and the second sprocket (728) are the same in size and shape.

10. The vacuum valve according to claim 9, characterized in that, The driving structure (73) includes a driving motor (731) fixedly installed on the movable frame (63). A tooth column (732) is fixed on the output end of the driving motor (731). A third gear (733) meshes with the tooth column (732), and the third gear (733) can slide on the tooth column (732). The third gear (733) is fixedly connected to one of the moving rods (712).

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