A gate valve body casting device, a gate valve production process and a gate valve

Abstract

The present application discloses a gate valve body casting device, a gate valve production process and a gate valve, which relates to the technical field of gate valve manufacturing, and includes a machine body, a core box, a blanking assembly, a sand core column and a compacting assembly. The core box includes a bottom plate and a shell, the bottom plate is mounted on the machine body, the shell is mounted on the upper end surface of the bottom plate, and a mold is fixedly mounted on the bottom plate, and the mold is located in the shell; the blanking assembly is mounted on the machine body, and the blanking assembly is used to pour sand into the core box; the sand core column is slidably mounted on the machine body and is located above the core box, and the machine body is provided with a first driving member that drives the sand core column to move in a vertical direction, and an air bag is wrapped on the outer peripheral wall of the sand core column, and the upper end of the air bag is connected to a vent pipe, and the end of the vent pipe away from the air bag is connected to an inflation and exhaust dual-purpose pump; the compacting assembly is used to compact the sand in the core box. The present application has the effect of being able to avoid the sand from falling into the mold cavity as much as possible, thereby improving the molding quality of the gate valve casting.

Description

Technical Field

[0001] The present application relates to the technical field of gate valve manufacturing, and in particular to a gate valve body casting device, a gate valve production process and a gate valve. Background Art

[0002] A gate valve is a valve that opens and closes by moving the opening and closing member (gate) in the vertical direction along the medium flow direction (channel axis). Among various types of valves, gate valves are the most widely used. Gate valves are mainly used to cut off the medium in pipelines, that is, they can be fully opened or fully closed. They can be used for low temperature and low pressure as well as high temperature and high pressure, and can be used for various media according to the different materials of the valve. Due to the relatively complex structure of the gate valve, the general way to manufacture the gate valve is through sand casting process.

[0003] Making sand molds is an important step in the gate valve manufacturing process. It mainly involves placing the mold in a core box, and then placing several sand core columns in the core box in a vertical direction. One end of the sand core column is in contact with the mold, and the other end of the sand core column extends out of the core box. Sand is then poured into the core box, and the sand in the core box is tamped and compacted to make the sand completely fit the outer wall of the mold and the sand core column. The sand core column is then taken out, and the aperture left after the sand core column is taken out is the pouring port for the subsequent pouring process.

[0004] However, in the above technology, since the sand fits closely with the outer wall of the sand core column after being compacted, when the sand core column is taken out, the sand core column will inevitably drive the sand in contact with it due to the friction factor, causing the inner wall of the aperture or the inner wall of the cavity to be damaged, and the sand falling from the damaged inner wall of the aperture or the inner wall of the cavity falls into the cavity. During the subsequent pouring process, the surface of the gate valve casting will be concave, thereby reducing the molding quality of the gate valve casting. Summary of the invention

[0005] The purpose of the present application is to provide a gate valve body casting device, a gate valve production process and a gate valve, which can avoid as much as possible the situation where sand falling from the damaged inner wall of the aperture or the inner wall of the cavity falls into the cavity when the sand core column is taken out, thereby improving the molding quality of the gate valve casting.

[0006] In the first aspect, a gate valve body casting device provided in the present application adopts the following technical solution:

[0007] Body;

[0008] The core box comprises a bottom plate and a shell, wherein the bottom plate is mounted on the machine body, the shell is mounted on the upper end surface of the bottom plate, a mold is fixedly mounted on the bottom plate, and the mold is located in the shell;

[0009] A material discharge assembly is installed on the machine body, and the material discharge assembly is used to pour sand into the core box;

[0010] The sand core column is slidably mounted on the machine body and is located above the core box. The machine body is provided with a first driving member for driving the sand core column to move in a vertical direction. An air bag is wrapped on the outer peripheral wall of the sand core column. The upper end of the air bag is connected to a vent pipe. The end of the vent pipe away from the air bag is connected to an inflation and exhaust dual-purpose pump;

[0011] The compacting assembly is used to compact the sand in the core box.

[0012] Optionally, a suction cup is provided on the lower end surface of the sand core column, the suction cup abuts against the surface of the mold, and the suction cup is connected to the airbag.

[0013] Optionally, the compaction assembly includes a pressure plate, which is slidably mounted on the machine body, the pressure plate is located above the core box, the area of ​​the pressure plate is equal to the area of ​​the opening on the upper end surface of the core box, and the machine body is provided with a second driving member for driving the pressure plate to move in a vertical direction. The pressure plate is provided with a clearance hole for the sand core column to pass through, and the aperture of the clearance hole is the same as the maximum diameter of the sand core column.

[0014] Optionally, the pressing plate comprises a plurality of tamping plates arranged in a rectangular array, the second driving member comprises a plurality of hydraulic cylinders arranged on the machine body in a rectangular array, a plurality of hydraulic rods correspond one-to-one to a plurality of tamping plates, and the make way holes are opened on several of the tamping plates.

[0015] Optionally, a lifting assembly for driving the core box to move up and down is further provided on the machine body, and the lifting assembly is connected to the bottom plate, and the lifting assembly can drive the core box to descend rapidly.

[0016] Optionally, the maximum diameter of the sand core column is larger than the diameter of the suction cup.

[0017] Optionally, a plurality of communication ports are provided between the suction cup and the airbag.

[0018] In a second aspect, the present application provides a gate valve production process, comprising the following steps:

[0019] S1: The sand core column is driven downward by the first driving member until the sand core column abuts against the mold, and at this time, the airbag on the sand core column is in an airless state;

[0020] S2: Start the feeding component to fill the core box with sand, and use the lifting component to drive the core box to move downward quickly, so that the sand is more compact, and then the compacting component further compacts the sand;

[0021] S3: Inflate the airbag of the sand core column through the dual-purpose pump for inflation and exhaust. The airbag expands and squeezes the surrounding sand to make the sand more compact. Then, deflate the airbag of the sand core column through the dual-purpose pump for inflation and exhaust. The airbag on the sand core column shrinks and does not contact the sand, making it easy to remove the sand core column.

[0022] S4: Pour the molten metal into the cavity from the aperture of the sand mold, wait for the molten metal to cool and form, and take out the molded casting;

[0023] S5: Grinding and painting the molded casting to obtain a gate valve.

[0024] In a third aspect, the present application provides a gate valve, comprising the following components by mass fraction:

[0025] Si: 7-8.5%; Fe: 0.1-0.3%; Cu: 0.1-0.3%; Mn: 0.3-0.35%; Mg: 0.1-0.5%; Cr: 0.1-0.2%; V: 0.01-0.02%; Nb: 50-100ppm; Sr: 0.01-0.03%; Rare earth elements: 20-100ppm.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] 1. When making sand molds, the sand core column is driven to move by the first driving member until the sand core column abuts against the surface of the mold, and then the sand is poured into the core box by the feeding assembly, and then the sand in the core box is compacted by the compacting assembly. At this time, the air bag on the sand core column is inflated by the air-inflating and air-extracting dual-purpose pump. The air bag will expand after inflation, and then begin to squeeze the sand around the air bag. During the squeezing process, the sand will become more compact, thereby further reducing the probability of sand core deformation, sand mold cracking, peeling, bubbles and other defects, thereby improving the overall quality of the casting; in addition, in the air bag After the expansion squeezes the sand, the diameter of the aperture formed by the sand core column becomes larger. Therefore, after the air is pumped out by the inflation and exhaust dual-purpose pump, the airbag begins to shrink, and the diameter of the sand core column is relatively reduced. The airbag on the outer peripheral wall of the sand core column will not touch the inner wall of the sand mold aperture, so when the sand core column is taken out, the sand core column is greatly reduced from scratching the inner wall of the aperture or the inner wall of the cavity, thereby avoiding the sand from falling into the cavity as much as possible, and then in the subsequent pouring process, the surface of the gate valve casting is avoided as much as possible, thereby further improving the molding quality of the gate valve casting;

[0028] 2. The setting of the suction cup. When the suction cup abuts against the surface of the mold, the airbag needs to be evacuated to reduce the diameter of the core column. At the same time, since the suction cup and the airbag are interconnected, the air pressure inside the suction cup will also decrease, so that the suction cup can be adsorbed relatively firmly on the surface of the mold. At the same time, the connection between the core column and the mold will be relatively more stable. Therefore, even when the compaction component compacts the sand in the core box, the core column will not slide relative to the mold due to the extrusion of the sand, thus minimizing the occurrence of looseness inside the sand mold caused by the movement of the core column, and further improving the forming quality of the gate valve casting; and when the sand is compacted, the airbag will be inflated, and the suction cup will be refilled with gas again. Therefore, the connection strength between the suction cup and the mold surface will also decrease, which does not affect the removal of the core column at all, and its overall operation is relatively convenient;

[0029] 3. The pressing plate in this application is composed of multiple ramming plates. Therefore, when compacting the sand, the sand at the edge part of the core box can be compacted first, and then the sand in the middle part of the core box can be compacted. The reason is that if the sand at the edge part is not compacted enough, it may cause the sand mold to deform or collapse during subsequent operations. Especially during the pouring process, the impact of the high-temperature molten metal may cause greater deformation of the unstable sand mold. Therefore, compacting the sand at the edge part first can form a stable framework, laying a foundation for the subsequent compaction of the middle part and the stability of the overall sand mold, improving the forming quality of the sand mold, and further improving the production quality of the casting; in addition, after the ramming plates compact all the sand in the middle part and the edge part of the core box, the ramming plates will combine into a pressing plate to continuously compact the sand as a whole. Since the airbag will cause extrusion to the sand during collision, resulting in the upward deformation of the molding sand, and the pressing plate continuously compacts the sand as a whole, its relative cooperation with the airbag can make the sand be further compacted and avoid the occurrence of the upward deformation of the sand, thereby further improving the compaction effect on the sand;

[0030] 4. The setting of the lifting component. On the one hand, it can cooperate with the relative movement of the compaction component and the core column, making the operating system of this equipment relatively simpler; on the other hand, the lifting component can drive the core box to quickly descend, and after the core box quickly descends and suddenly stops, the sand inside it will continue to move downward due to inertia, so that the sand inside the core box is further compacted, thereby further improving the stability of the molding sand and the production quality of the casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the overall structural schematic diagram of Embodiment 2 of the present application;

[0032] Figure 2 is the structural schematic diagram of the first driving part in Embodiment 2 of the present application;

[0033] Figure 3 It is a schematic structural diagram of the first driving member hiding the mounting plate in Embodiment 2 of the present application;

[0034] Figure 4 It is a schematic structural diagram of the core sand column in Embodiment 2 of the present application;

[0035] Figure 5 is Figure 4 an enlarged schematic view of part A in

[0036] In the figure, 1 is the machine body; 2 is the core box; 21 is the bottom plate; 22 is the housing; 3 is the blanking assembly; 31 is the discharge box; 32 is the blanking pipe; 4 is the core sand column; 41 is the airbag; 411 is the suction cup; 412 is the communication port; 42 is the ventilation pipe; 43 is the inflation and air extraction dual-purpose pump; 5 is the compaction assembly; 51 is the pressing plate; 511 is the ramming plate; 512 is the relief hole; 52 is the hydraulic cylinder; 6 is the first driving member; 61 is the mounting plate; 62 is the electric push rod; 7 is the lifting assembly. Specific Embodiments

[0037] The following will Figures 1 - 5 further elaborate on the present application in conjunction with the attached Embodiment 1

[0038] A gate valve, by mass fraction ratio, includes the following components:

[0039] Si: 7 - 8.5%; Fe: 0.1 - 0.3%; Cu: 0.1 - 0.3%; Mn: 0.3 - 0.35%; Mg: 0.1 - 0.5%; Cr: 0.1 - 0.2%; V: 0.01 - 0.02%; Nb: 50 - 100 ppm; Sr: 0.01 - 0.03%; rare earth elements: 20 - 100 ppm.

[0040] The rare earth element in this embodiment is set as La. The material used for the gate valve in the embodiment of the present invention is aluminum alloy. Therefore, the aluminum alloy gate valve in the embodiment of the present invention has high strength, excellent plasticity and toughness, and corrosion resistance, and can also meet the requirements of automotive thin-walled structural parts such as shock towers, rear vehicle bodies, longitudinal beams, and front compartments. In addition, the aluminum alloy die-castings of the embodiment of the present invention can be obtained without heat treatment, which can effectively simplify the processing process, avoid deformation, and improve the qualification rate of aluminum alloy die-castings. Embodiment 2

[0041] A gate valve body casting device, referring to Figures 1 - 5 , includes a machine body 1, a core box 2, a blanking assembly 3, a core sand column 4, and a compaction assembly 5.

[0042] The core box 2 in this embodiment includes a bottom plate 21 and a housing 22. The bottom plate 21 is installed on the machine body 1, and the housing 22 is installed on the upper end surface of the bottom plate 21. In this embodiment, the housing 22 and the bottom plate 21 are connected by a buckle (not shown in the figure) to facilitate the installation and

[0043] disassembly of the housing 22. A mold is also fixedly installed on the bottom plate 21, and the mold is located inside the housing 22.

[0044] In this embodiment, the blanking assembly 3 mainly includes a discharge box 31 for storing sand and a blanking pipe 32. The discharge box 31 is installed on the machine body 1. The blanking pipe 32 in this embodiment is set as a flexible pipe. One end of the blanking pipe 32 is communicated with the discharge box 31, and the other end of the blanking pipe 32 is movably installed on the machine body 1. And the end of the blanking pipe 32 away from the discharge box 31 can be rotated above the core box 2. A pump is also provided between the blanking pipe 32 and the discharge box 31 to facilitate the transportation of sand.

[0045] In this embodiment, there are two sand core columns 4. Both of the two sand core columns 4 are slidably installed on the machine body 1 and are located above the core box 2. A first driving member 6 for driving the sand core columns 4 to move in the vertical direction is provided on the machine body 1. An airbag 41 is wrapped around the outer peripheral wall of the sand core column 4. The upper end of the airbag 41 is communicated with a ventilation pipe 42, and one end of the ventilation pipe 42 away from the airbag 41 is connected with a pump 43 for both inflation and deflation;

[0046] The compaction assembly 5 is installed on the machine body 1. In this embodiment, the compaction assembly 5 is used to compact the sand in the core box 2.

[0047] When molding sand is required, the housing 22 is installed on the bottom plate 21 to form the core box 2. Then, the air inflation and extraction dual-purpose pump 43 is started to evacuate the gas in the outer airbag 41 of the core sand column 4. Next, the first driving member 6 drives the core sand column 4 to move in the vertically downward direction until the bottom end of the core sand column 4 abuts against the surface of the mold on the bottom plate 21. Then, the nozzle of the feeding pipe 32 is rotated above the core box 2, and the pump on the discharging box 31 is started. After the core box 2 is filled with sand, the compaction assembly 5 is started to compact the sand in the core box 2. Then, the air inflation and extraction dual-purpose pump 43 is started again to inflate the outer airbag 41 of the core sand column 4. After inflation, the airbag 41 will expand to further extrude the sand in the core box 2. During the extrusion process, the sand will become more compact, thereby further reducing the probability of defects such as core sand deformation, sand mold cracking, peeling, and air bubbles, and thus improving the overall quality of the casting. In addition, after the airbag 41 expands and extrudes the sand, the diameter of the aperture formed by the core sand column 4 becomes larger. Therefore, after the air inflation and extraction dual-purpose pump 43 evacuates the air, the airbag 41 begins to contract, and the diameter of the core sand column 4 relatively decreases. Moreover, the airbag 41 on the outer peripheral wall of the core sand column 4 does not touch the inner wall of the sand mold aperture. Therefore, when the core sand column 4 is taken out, the scraping of the inner wall of the aperture or the inner wall of the cavity by the core sand column 4 is greatly reduced, thereby minimizing the situation where sand falls into the cavity. Furthermore, during the subsequent pouring process, the situation where the surface of the gate valve casting shows depressions is minimized, and thus the forming quality of the gate valve casting is further improved.

[0048] Among them, referring to Figure 3 and Figure 5 , in this embodiment, a suction cup 411 is provided on the lower end surface of the core sand column 4, and the suction cup 411 in this embodiment is communicated with the airbag 41.

[0049] When the core column 4 needs to be abutted against the mold on the bottom plate 21, the suction cup 411 can be abutted against the surface of the mold. Therefore, when the inflatable and exhaust dual-purpose pump 43 is started to exhaust the airbag 41, since the suction cup 411 and the airbag 41 are interconnected, the air pressure in the suction cup 411 will also decrease, and a relative vacuum can be formed between the suction cup 411 and the mold surface, so that the suction cup 411 can be relatively firmly adsorbed on the mold surface. At the same time, the connection between the core column 4 and the mold will be relatively more stable. Therefore, even when the compaction component 5 compacts the sand in the core box 2, the core column 4 will not slide relative to the mold due to the extrusion of the sand, thus minimizing the occurrence of looseness inside the sand mold caused by the movement of the core column 4, and further improving the forming quality of the gate valve casting. And when the sand is compacted, the airbag 41 will be inflated, and the suction cup 411 will be refilled with gas. Therefore, the connection strength between the suction cup 411 and the mold surface will also decrease, which does not affect the removal of the core column 4 at all, and its overall operation is relatively convenient.

[0050] In addition, usually, after a sand mold is made, there will be some remaining sand on the bottom plate 21 and the mold on the bottom plate 21. At this time, it is necessary to clean the bottom plate 21 and the mold surface. In this embodiment, the settings of the airbag 41, the ventilation pipe 42, and the inflatable and exhaust dual-purpose pump 43 can completely serve as a blowing device. When the bottom plate 21 and the mold need to be cleaned, the suction cup 411 on the core column 4 can be moved above the suspended bottom plate 21 and the mold, and then the inflatable and exhaust dual-purpose pump 43 is started to inflate the airbag 41, and the excess gas will be ejected from the connection between the airbag 41 and the suction cup 411, thus forming a blowing wind, and the formed blowing wind just blows towards the bottom plate 21 and the mold, thereby achieving the effect of cleaning the sand on the bottom plate 21 and the mold surface.

[0051] At the same time, in order to further enhance the cleaning effect of the suction cup 411 and the airbag 41 on the bottom plate 21 and the mold, a communication port 412 is provided between the suction cup 411 and the airbag 41 in this embodiment, that is, multiple blowing ports are added, thereby increasing the area that the suction cup 411 can blow, and further improving the cleaning effect of the suction cup 411 and the airbag 41 on the bottom plate 21 and the mold.

[0052] It should be noted that the maximum diameter of the core column 4 in this embodiment is larger than the diameter of the suction cup 411, that is, after the airbag 41 on the core column 4 expands, the diameter of the core column 4 is larger than the diameter of the suction cup 411. Therefore, after the airbag 41 on the core column 4 expands, the diameter of the hole formed on the sand mold will also be larger than the diameter of the suction cup 411. Therefore, when the core column 4 is removed, the suction cup 411 will not contact the inside of the hole diameter on the sand mold, thus minimizing the occurrence of sand falling into the cavity.

[0053] Refer toFigure 2 , Figure 3 and Figure 4 The compaction assembly 5 in this embodiment includes a pressing plate 51, which is slidably mounted on the machine body 1. The pressing plate 51 is located above the core box 2. The area of ​​the pressing plate 51 is equal to the area of ​​the opening on the upper end surface of the core box 2. The machine body 1 is provided with a second driving member for driving the pressing plate 51 to move in the vertical direction. A clearance hole 512 for the sand core column 4 to pass through is opened on the compaction plate, and the aperture of the clearance hole 512 is the same as the maximum diameter of the sand core column 4.

[0054] When the suction cup 411 on the sand core column 4 is firmly adsorbed on the mold surface and the core box 2 is filled with sand, the second driving member is started to drive the pressure plate 51 to move downward until the pressure plate 51 abuts against the upper layer of sand in the core box 2. As the pressure plate 51 continues to descend, the upper layer of sand in the core box 2 continues to move downward until the space components between the sand are reduced until they disappear, thereby achieving the compaction effect of the sand.

[0055] At the same time, after the pressure plate 51 compacts the sand in the core box 2, the subsequent operation is to expand the airbag 41 to continue to squeeze the sand in the core box 2. When the airbag 41 squeezes the inside of the aperture formed by the sand core column 4, the sand close to the upper end of the aperture can move upward due to the squeezing of the airbag 41, thereby causing the molding sand to deform upward. The pressure plate 51 continues to compact the sand downward as a whole, and its cooperation with the airbag 41 can further compact the sand and avoid the upward deformation of the sand, thereby maintaining the integrity of the overall molding sand, thereby further improving the compaction effect of the sand.

[0056] Among them, refer to Figure 1 and Figure 2 The first driving member 6 in this embodiment includes a mounting plate 61 and an electric push rod 62. The mounting plate 61 is slidably mounted on the machine body 1, and the mounting plate 61 is located directly above the core box 2. The electric push rod 62 is mounted on the machine body 1, and the output shaft of the electric push rod 62 is fixedly connected to the mounting plate 61.

[0057] Reference Figure 3 and Figure 4 The pressing plate 51 in this embodiment includes a plurality of tamping plates 511, which are arranged in a rectangular array. The second driving member includes a plurality of hydraulic cylinders 52, which are also arranged in a rectangular array on the mounting plate 61. The plurality of hydraulic rods correspond one to one with the plurality of tamping plates 511. The tamping plates 511 are fixedly mounted on the output shafts of the corresponding hydraulic cylinders 52, and the clearance holes 512 are provided on several of the tamping plates 511.

[0058] The arrangement of multiple ramming plates 511 can locally compact the sand in the core box 2. Therefore, when compacting the sand, the sand at the edge part inside the core box 2 can be first compacted by the ramming plates 511 at the edge part of the mounting plate 61, and then the sand at the middle part of the core box 2 can be compacted. The reason is that if the sand at the edge part is insufficiently compacted, it may cause the sand mold to deform or collapse during subsequent operations. Especially during the pouring process, the impact of the high-temperature molten metal may cause greater deformation of the unstable sand mold. Therefore, compacting the sand at the edge part first can form a stable framework, laying a foundation for the subsequent compaction of the middle part and the stability of the overall sand mold, improving the forming quality of the sand mold, and further improving the production quality of the casting.

[0059] Meanwhile, in this embodiment, multiple ramming plates 511 can also move up and down synchronously. At this time, the ramming plates 511 can serve as the pressing plates 51 mentioned above.

[0060] Finally, a lifting assembly 7 is also provided on the machine body 1 in this embodiment. The lifting assembly 7 in this embodiment is set as a cylinder. The cylinder in the lifting assembly 7 is arranged on the lower end surface of the bottom plate 21. The bottom plate 21 in this embodiment is slidably mounted on the machine body 1, and the lifting assembly 7 can drive the core box 2 to quickly rise or fall.

[0061] Therefore, when the sand in the core box 2 is filled, the lifting assembly 7 can drive the core box 2 to quickly descend, and after the core box 2 quickly descends and suddenly stops, the sand inside it will continue to move downward due to inertia, so that the sand inside the core box 2 is further compacted, further improving the stability of the molding sand and the production quality of the casting; in addition, it can cooperate with the relative movement of the compaction assembly 5 and the core sand column 4, making the operating system of this equipment relatively simpler.

[0062] Working principle of a gate valve body casting device: When molding sand is required, the housing 22 is installed on the bottom plate 21 to form the core box 2. Then, the air inflation and suction dual-purpose pump 43 is started to evacuate the gas in the outer airbag 41 of the sand core column 4. Next, the electric push rod 6 is started to extend through the control center, thereby driving the mounting plate 61 and the sand core column 4 to move in the vertically downward direction until the suction cup 411 at the bottom end of the sand core column 4 abuts against the surface of the mold on the bottom plate 21. Then, the air inflation and suction dual-purpose pump 43 is started again to extract the gas between the suction cup 411 and the mold so that the suction cup 411 can tightly adsorb on the surface of the mold. Then, the nozzle of the material feeding pipe 32 is rotated above the core box 2, and the pump on the discharging box 31 is started. After the core box 2 is filled with sand, the cylinder and the electric push rod 62 in the lifting assembly 7 are simultaneously started through the control center. The contraction amount of the cylinder in the lifting assembly 7 is the same as the extension amount of the electric push rod 62, and the control center controls the contraction speed of the cylinder and the extension speed of the electric push rod 62 to be the same. Therefore, the sand core column 4 can move downward synchronously with the core box 2, and the cylinder drives the core box 2 to quickly descend. After the core box 2 quickly descends and suddenly stops, the sand inside it will continue to move downward due to inertia, so that the sand inside the core box 2 is initially compacted. Then, multiple hydraulic cylinders 52 on the mounting plate 61 are started. The output shaft of the hydraulic cylinder 52 descends, driving the tamping plate 511 on the output shaft to move in the direction close to the sand in the core box 2. After the sand in the core box 2 is tamped again by the tamping plate 511, the tamping plate 511 is combined into a pressing plate 51 through the control of the hydraulic cylinder 52 to continuously press the sand in the core box 2 as a whole. Then, the air inflation and suction dual-purpose pump 43 is started again to inflate the outer airbag 41 of the sand core column 4. After the airbag 41 is inflated, it will expand to squeeze the sand in the core box 2 again. During the squeezing process, the sand will become more compact. After the airbag 41 expands and squeezes the sand, the diameter of the pore formed by the sand core column 4 becomes larger. Therefore, after the air inflation and suction dual-purpose pump 43 evacuates the air, the airbag 41 begins to contract (there is still some gas left in the airbag to release the negative pressure adsorption state of the suction cup). The diameter of the sand core column 4 relatively decreases, and the airbag 41 on the outer peripheral wall of the sand core column 4 does not touch the inner wall of the sand mold pore. Thus, when the sand core column 4 is taken out, the scratching of the inner wall of the pore or the inner wall of the cavity by the sand core column 4 is greatly reduced, thereby minimizing the situation of sand falling into the cavity. Furthermore, during the subsequent pouring process, the situation of depressions on the surface of the gate valve casting is minimized, and further improves the forming quality of the gate valve casting. Embodiment 3

[0063] A gate valve production process, based on the above-mentioned gate valve body casting device, includes the following steps:

[0064] S1: Drive the core sand column 4 downward through the first driving member 6 until the core sand column 4 abuts against the mold. At this time, the airbag 41 on the core sand column 4 is in a non-gas state;

[0065] S2: Start the feeding assembly 3 to fill the core box 2 with sand, and drive the core box 2 to move downward rapidly through the lifting assembly 7 to make the sand more compact. Then, further compact the sand through the compaction assembly 5;

[0066] S3: Inflate the airbag 41 of the core sand column 4 through the air inflation and deflation dual-purpose pump 43. The airbag 41 expands and squeezes the surrounding sand to make the sand more compact. Then, deflate the airbag 41 of the core sand column 4 through the air inflation and deflation dual-purpose pump 43. The airbag 41 on the core sand column 4 contracts and does not contact the sand, facilitating the removal of the core sand column 4;

[0067] S4: Pour the molten metal into the cavity from the aperture of the sand mold. Wait for the molten metal to cool and solidify, and then take out the formed casting;

[0068] S5: Grind and paint the formed casting to obtain a gate valve.

[0069] Before step S1, various metals will also be melted through a furnace to obtain molten metal with a perfect ratio. Then, in S4, the molten metal with a good ratio will be poured, and finally, a complete gate valve will be obtained through S5. Through this process, products with high forming quality can be manufactured.

[0070] The embodiments of this specific implementation manner are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. The same components are denoted by the same reference numerals. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A gate valve production process, based on a gate valve body casting device, comprises the following steps: S1: The sand core column (4) is driven downward by the first driving member (6) until the sand core column (4) abuts against the mold, and at this time, the air bag (41) on the sand core column (4) is in an airless state; S2: starting the feeding component (3) to fill the core box (2) with sand, and driving the core box (2) to move downward quickly through the lifting component (7) to make the sand more compact, and then further compacting the sand through the compacting component (5); S3: Inflate the airbag (41) of the sand core column (4) by using the air-inflating and air-exhausting dual-purpose pump (43), so that the airbag (41) expands and squeezes the surrounding sand to make the sand more compact, and then deflate the airbag (41) of the sand core column (4) by using the air-inflating and air-exhausting dual-purpose pump (43), so that the airbag (41) on the sand core column (4) contracts and does not contact the sand, so that the sand core column (4) can be easily removed; S4: Pour the molten metal into the cavity from the aperture of the sand mold, wait for the molten metal to cool and form, and take out the molded casting; S5: grinding and painting the molded casting to obtain a gate valve; The gate valve body casting device comprises: Body (1); A core box (2) comprising a bottom plate (21) and a shell (22), wherein the bottom plate (21) is mounted on the machine body (1), and the shell (22) is mounted on the upper end surface of the bottom plate (21); a mold is also fixedly mounted on the bottom plate (21), and the mold is located inside the shell (22); A material discharge assembly (3) is mounted on the machine body (1), and the material discharge assembly (3) is used to pour sand into the core box (2); A sand core column (4) is slidably mounted on the machine body (1) and is located above the core box (2); a first driving member (6) is provided on the machine body (1) for driving the sand core column (4) to move in a vertical direction; an air bag (41) is wrapped around the outer peripheral wall of the sand core column (4); an upper end of the air bag (41) is connected to a ventilation pipe (42); and an end of the ventilation pipe (42) away from the air bag (41) is connected to an inflation and degassing dual-purpose pump (43); A compacting assembly (5) is used to compact the sand in the core box (2).

2. The production process of a gate valve according to claim 1, characterized in that, A suction cup (411) is provided on the lower end surface of the sand core column (4), the suction cup (411) abuts against the surface of the mold, and the suction cup (411) is connected to the air bag (41).

3. A production process of a gate valve according to claim 2, characterized in that, The compacting assembly (5) comprises a pressing plate (51), the pressing plate (51) being slidably mounted on the machine body (1), the pressing plate (51) being located above the core box (2), the area of ​​the pressing plate (51) being equal to the area of ​​the opening on the upper end surface of the core box (2), the machine body (1) being provided with a second driving member for driving the pressing plate (51) to move in a vertical direction, the pressing plate (51) being provided with a clearance hole (512) for the sand core column (4) to pass through, the aperture of the clearance hole (512) being equal to the maximum diameter of the sand core column (4).

4. A production process of a gate valve according to claim 3, characterized in that, The pressing plate (51) comprises a plurality of ramming plates (511) arranged in a rectangular array. The second driving member includes a plurality of hydraulic cylinders (52) which are also arranged on the machine body (1) in a rectangular array. The plurality of hydraulic cylinders (52) correspond to the plurality of ramming plates (511) one by one. The relief holes (512) are formed in several of the ramming plates (511).

5. A production process of a gate valve according to claim 4, characterized in that, An elevating assembly (7) for driving the core box (2) to move up and down is further provided on the machine body (1). The elevating assembly (7) is connected to the bottom plate (21), and the elevating assembly (7) can drive the core box (2) to rapidly descend.

6. The production process of a gate valve according to claim 2, characterized in that, The maximum diameter of the sand core column (4) is larger than the diameter of the suction cup (411).

7. A production process of a gate valve according to claim 6, characterized in that, A plurality of communication ports (412) are provided between the suction cup (411) and the air bag (41).

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