Gate valve body casting device, gate valve production process and gate valve

Abstract

The invention discloses a gate valve body casting device, a gate valve production process and a gate valve, and relates to the technical field of gate valve manufacturing, the gate valve body casting device comprises a machine body, a core box, a discharging assembly, a sand core column and a compaction assembly, the core box comprises a bottom plate and a shell, the bottom plate is installed on the machine body, the shell is installed on the upper end face of the bottom plate, a mold is further fixedly installed on the bottom plate, and the mold is located in the shell; the discharging assembly is installed on the machine body and used for pouring sand into the core box. The sand core column is installed on the machine body in a sliding mode and located above the core box, a first driving piece for driving the sand core column to move in the vertical direction is arranged on the machine body, the peripheral wall of the sand core column is wrapped with an air bag, the upper end of the air bag communicates with a ventilation pipe, and the end, away from the air bag, of the ventilation pipe is connected with an air inflation and exhaust dual-purpose pump; and the compacting assembly is used for compacting the sand in the core box. The mold has the advantages that sand can be prevented from falling into the mold cavity as much as possible, and therefore the forming quality of a gate valve casting is improved.

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: Body; 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; A material discharge assembly is installed on the machine body, and 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. 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; The compacting assembly is used to compact the sand in the core box.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] Optionally, the maximum diameter of the sand core column is larger than the diameter of the suction cup.

[0012] Optionally, a plurality of communication ports are provided between the suction cup and the airbag.

[0013] In a second aspect, the present application provides a gate valve production process, comprising the following steps: 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; 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; 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. 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.

[0014] In a third aspect, the present application provides a gate valve, comprising the following components by mass fraction: 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.

[0015] In summary, the present application includes at least one of the following beneficial technical effects: 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; 2. The setting of the suction cup. When the suction cup abuts against the surface of the mold, the air bag needs to be evacuated to reduce the diameter of the sand core column. At the same time, since the suction cup and the air bag are interconnected, the air pressure in the suction cup will also be reduced, so that the suction cup can be relatively firmly adsorbed on the surface of the mold. At the same time, the connection between the sand core column and the mold will be relatively more stable. Therefore, even when the compaction component compacts the sand in the core box, the sand core column will not slide relative to the mold due to the extrusion of the sand, thereby avoiding the looseness of the sand mold due to the movement of the sand core column, thereby further improving the molding quality of the gate valve casting; and when the sand is compacted, the air bag will be inflated, and the suction cup will be refilled with gas, so the connection strength between the suction cup and the mold surface will also be reduced, which will not affect the removal of the sand core column at all, and the overall operation is relatively convenient; 3. The pressing plate in the present application is composed of multiple tamping plates. Therefore, when compacting the sand, the sand at the edge of the core box can be compacted first, and then the sand in the middle of the core box can be compacted. The reason is that if the sand at the edge is not compacted enough, it may cause the sand mold to deform or collapse in subsequent operations. In particular, during the pouring process, the impact of high-temperature molten metal may cause the unstable sand mold to deform more. Therefore, compacting the sand at the edge first can form a stable frame, which is conducive to the subsequent compaction of the middle part and the stability of the overall sand mold. It lays a qualitative foundation, improves the molding quality of the sand mold, and thus improves the production quality of the castings; in addition, after the tamping plate compacts all the sand in the middle and edge parts of the core box, the tamping plate will be combined with the pressing plate to continuously compact the sand as a whole. Since the airbag will squeeze the sand during the collision, the molding sand will deform upward, and the pressing plate will continuously compact the sand as a whole. The cooperation with the airbag can further compact the sand and avoid the upward deformation of the sand, thereby further improving the compaction effect of the sand; 4. The setting of the lifting component, on the one hand, can cooperate with the relative movement of the compacting component and the sand core column, making the operating system of the equipment relatively simpler; on the other hand, the lifting component can drive the core box to descend rapidly, and the core box suddenly stops after rapid descent, and 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 castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of Example 2 of the present application; Figure 2 is a schematic structural diagram of the first driving member in Example 2 of the present application; Figure 3This is a schematic structural diagram of the first driving member in Example 2 of the present application without the mounting plate; Figure 4 It is a schematic diagram of the structure of the sand core column in Example 2 of the present application; Figure 5 yes Figure 4 The enlarged schematic diagram of point A in the middle; In the figure, 1. machine body; 2. core box; 21. bottom plate; 22. shell; 3. unloading assembly; 31. discharge box; 32. unloading pipe; 4. sand core column; 41. air bag; 411. suction cup; 412. connecting port; 42. ventilation pipe; 43. inflation and exhaust pump; 5. compaction assembly; 51. pressure plate; 511. tamping plate; 512. clearance hole; 52. hydraulic cylinder; 6. first driving member; 61. mounting plate; 62. electric push rod; 7. lifting assembly. DETAILED DESCRIPTION

[0017] The following is combined with Figure 1-5 , further details of this application are given. Example 1

[0018] A gate valve, comprising the following components by mass fraction: 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.

[0019] The rare earth element in this embodiment is set to La, and the material used for the gate valve in the embodiment of the present invention is aluminum alloy. Therefore, the aluminum alloy pressure gate valve in the embodiment of the present invention has high strength and excellent plasticity, toughness and corrosion resistance. It can also meet the needs of automobile thin-walled structural parts such as shock towers, rear bodies, longitudinal beams and front cabins. In addition, the aluminum alloy die-casting in the embodiment of the present invention can be obtained without heat treatment, which can effectively simplify the processing technology, avoid deformation, and improve the qualified rate of aluminum alloy die-castings. Example 2

[0020] A gate valve body casting device, referring to Figure 1-Figure 5 , including a machine body 1, a core box 2, a material discharge component 3, a sand core column 4 and a compaction component 5.

[0021] The core box 2 in this embodiment includes a bottom plate 21 and a shell 22. The bottom plate 21 is mounted on the body 1, and the shell 22 is mounted on the upper end surface of the bottom plate 21. The shell 22 in this embodiment is connected to the bottom plate 21 by a buckle (not shown in the figure) to facilitate the installation and The bottom plate 21 is also fixedly mounted with a mold, and the mold is located inside the shell 22 .

[0022] In this embodiment, the discharge assembly 3 mainly includes a discharge box 31 for storing sand and a discharge pipe 32. The discharge box 31 is installed on the machine body 1. The discharge pipe 32 in this embodiment is configured as a hose. One end of the discharge pipe 32 is connected to the discharge box 31, and the other end of the discharge pipe 32 is movably mounted on the machine body 1. The end of the discharge pipe 32 away from the discharge box 31 can be rotated to the top of the core box 2. A pump is also provided between the discharge pipe 32 and the discharge box 31 to transport the sand.

[0023] In this embodiment, two sand core columns 4 are provided, and both sand core columns 4 are slidably mounted on the machine body 1 and are located above the core box 2. The machine body 1 is provided with a first driving member 6 for driving the sand core column 4 to move in a vertical direction. An air bag 41 is wrapped on the outer peripheral wall of the sand core column 4, and a vent pipe 42 is connected to the upper end of the air bag 41. An end of the vent pipe 42 away from the air bag 41 is connected to an inflation and exhaust dual-purpose pump 43; The compacting assembly 5 is mounted on the machine body 1 . The compacting assembly 5 in this embodiment is used to compact the sand in the core box 2 .

[0024] When it is necessary to cast molding sand, the shell 22 is installed on the base plate 21 to form a core box 2, and then the inflation and exhaust dual-purpose pump 43 is started to exhaust the gas in the outer air bag 41 of the sand core column 4, and then the sand core column 4 is driven to move in a vertical downward direction through the first driving member 6 until the bottom end of the sand core column 4 abuts against the surface of the mold on the base plate 21, and then the nozzle of the discharge pipe 32 is rotated to the top of the core box 2, and the pump on the discharge box 31 is started. After the sand in the core box 2 is full, the compaction component 5 is started to compact the sand in the core box 2, and then the inflation and exhaust dual-purpose pump 43 is started again to inflate the outer air bag 41 of the sand core column 4. After inflation, the air bag 41 will expand to squeeze the sand in the core box 2 again. During the squeezing process, the sand will become more compact, thereby The probability of sand core deformation, sand mold cracking, peeling, bubbles and other defects is further reduced, thereby improving the overall quality of the casting; in addition, after the air bag 41 expands and squeezes the sand, the diameter of the aperture formed by the sand core column 4 becomes larger. Therefore, after the air is evacuated by the inflation and exhaust dual-purpose pump 43, the air bag 41 begins to shrink, and the diameter of the sand core column 4 is relatively reduced. The air bag 41 on the outer wall of the sand core column 4 will not touch the inner wall of the sand mold aperture, so that when the sand core column 4 is taken out, the sand core column 4 is greatly reduced. The scratching of the inner wall of the aperture or the inner wall of the cavity is greatly reduced, thereby minimizing the occurrence of sand falling into the cavity, and then in the subsequent pouring process, the surface of the gate valve casting is avoided as much as possible. The molding quality of the gate valve casting is further improved.

[0025] Among them, refer to Figure 3 and Figure 5 In this embodiment, a suction cup 411 is provided on the lower end surface of the sand core column 4, and the suction cup 411 in this embodiment is connected to the air bag 41.

[0026] When the sand core column 4 needs to be butted against the mold on the bottom plate 21, the suction cup 411 can be butted against the surface of the mold. Therefore, when the air pump 43 is started to evacuate the air bag 41, since the suction cup 411 and the air bag 41 are interconnected, the air pressure in the suction cup 411 will also decrease, and the suction cup 411 and the mold surface can form a relative vacuum, so that the suction cup 411 can be relatively firmly adsorbed on the surface of the mold, and the connection between the sand core column 4 and the mold will be relatively more stable. Therefore, even during compaction, the suction cup 411 can be relatively firmly adsorbed on the surface of the mold. When the component 5 compacts the sand in the core box 2, the sand core column 4 will not slide relative to the mold due to the squeezing of the sand, thereby avoiding as much as possible the loosening of the sand mold due to the movement of the sand core column 4, thereby further improving the molding 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, so the connection strength between the suction cup 411 and the mold surface will also be reduced, which will not affect the removal of the sand core column 4 at all, and the overall operation is relatively convenient.

[0027] In addition, under normal circumstances, after a sand mold is made, some sand will remain on the bottom plate 21 and the mold on the bottom plate 21. At this time, the bottom plate 21 and the surface of the mold need to be cleaned. The air bag 41, the vent pipe 42 and the inflation and exhaust dual-purpose pump 43 in this embodiment can be used as a blowing device. When it is necessary to clean the bottom plate 21 and the mold, the suction cup 411 on the sand core column 4 is moved to the top of the suspended bottom plate 21 and the mold, and then the inflation and exhaust dual-purpose pump 43 is started to inflate the air bag 41, and the excess gas will be ejected from the connection between the air bag 41 and the suction cup 411, thereby forming a blow, and the formed blow 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 surface of the mold.

[0028] At the same time, in order to further enhance the cleaning effect of the suction cup 411 and the air bag 41 on the bottom plate 21 and the mold, a connecting port 412 is provided between the suction cup 411 and the air bag 41 in the present embodiment, that is, a plurality of blowing ports are added, thereby increasing the area that the suction cup 411 can blow, thereby improving the cleaning effect of the suction cup 411 and the air bag 41 on the bottom plate 21 and the mold.

[0029] It should be noted that in the present embodiment, the maximum diameter of the sand core column 4 is larger than the diameter of the suction cup 411, that is, after the air bag 41 on the sand core column 4 is expanded, the diameter of the sand core column 4 is larger than the diameter of the suction cup 411. Therefore, after the air bag 41 on the sand core column 4 is expanded, the diameter of the aperture formed by it on the sand mold will also be larger than the diameter of the suction cup 411. Therefore, when the sand core column 4 is taken out, the suction cup 411 will not contact the inside of the aperture on the sand mold, thereby minimizing the occurrence of sand falling into the mold cavity.

[0030] Reference Figure 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] Reference Figure 3 and Figure 4The 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.

[0035] The setting of multiple tamping plates 511 can locally compact the sand in the core box 2. Therefore, when compacting the sand, the sand in the edge part of the core box 2 can be compacted first by the tamping plates 511 at the edge part of the mounting plate 61, and then the sand in the middle part of the core box 2 can be compacted. The reason is that if the sand in the edge part is not compacted enough, it may cause the sand mold to deform or collapse in subsequent operations. In particular, during the pouring process, the impact of high-temperature molten metal may cause the unstable sand mold to produce greater deformation. Therefore, compacting the sand in the edge part first can form a stable frame, which lays the foundation for the subsequent compaction of the middle part and the stability of the overall sand mold, improves the molding quality of the sand mold, and thus improves the production quality of the casting.

[0036] At the same time, in this embodiment, multiple tamping plates 511 can also move up and down synchronously. At this time, the tamping plates 511 can serve as the above-mentioned pressing plates 51.

[0037] Finally, a lifting assembly 7 is also provided on the machine body 1 in this embodiment. The lifting assembly 7 in this embodiment is configured as a cylinder. The cylinder in the lifting assembly 7 is provided on the lower end surface of the bottom plate 21. The bottom plate 21 in this embodiment is slidably installed on the machine body 1. The lifting assembly 7 can drive the core box 2 to rise or fall quickly.

[0038] Therefore, when the sand in the core box 2 is full, the lifting assembly 7 can drive the core box 2 to descend rapidly, and the core box 2 suddenly stops after the rapid descent, and the sand inside it will continue to move downward due to inertia, so that the sand inside the core box 2 is further compacted, thereby 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 compacting assembly 5 and the sand core column 4, making the operating system of the equipment relatively simpler.

[0039] The working principle of a gate valve body casting device: when it is necessary to cast molding sand, the shell 22 is installed on the bottom plate 21 to form a core box 2, and then the inflation and exhaust dual-purpose pump 43 is started to evacuate the gas in the outer air bag 41 of the sand core column 4, and then 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 a vertical 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, and then the inflation and exhaust 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 be tightly adsorbed on the surface of the mold, and then the nozzle of the discharge pipe 32 is rotated The sand core column 4 is moved downwards synchronously with the core box 2, and the cylinder drives the core box 2 to descend rapidly. After the core box 2 is rapidly descended, the core box 2 stops suddenly, and the sand inside it continues to move downwards due to inertia, so that the sand inside the core box 2 is preliminarily compacted, and then the multi-stage sand pump on the mounting plate 61 is started. A hydraulic cylinder 52 is provided, and 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 tamping plate 511 compacts the sand in the core box 2 again, the tamping plate 511 is controlled by the hydraulic cylinder 52 to form a pressure plate 51 and continuously pressurize the sand in the core box 2 as a whole. Then, the air-inflating and air-extracting dual-purpose pump 43 is started again to inflate the outer airbag 41 of the sand core column 4. After being inflated, the airbag 41 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 sand core column 4 is formed. The diameter of the aperture becomes larger, therefore, after the air is evacuated by the inflation and exhaust dual-purpose pump 43, the airbag 41 begins to shrink (some gas remains in the airbag to release the negative pressure adsorption state of the suction cup), and the diameter of the sand core column 4 is relatively reduced, and the airbag 41 on the outer peripheral wall of the sand core column 4 will not touch the inner wall of the sand mold aperture, so that when the sand core column 4 is taken out, the sand core column 4 greatly reduces the possibility of scratching the inner wall of the aperture or the inner wall of the cavity, thereby avoiding the sand 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. Example 3

[0040] A gate valve production process, based on the above-mentioned 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: Start the feeding assembly 3 to fill the core box 2 with sand, and drive the core box 2 to move downward quickly through the lifting assembly 7 to make the sand more compact, and then further compact the sand through the compacting assembly 5; S3: Inflate the airbag 41 of the sand core column 4 through the air-inflating and air-exhausting dual-purpose pump 43, the airbag 41 expands, squeezes the surrounding sand, and makes the sand more compact, and then deflate the airbag 41 of the sand core column 4 through the air-inflating and air-exhausting dual-purpose pump 43, the airbag 41 on the sand core column 4 shrinks and does not contact the sand, so that the sand core column 4 is convenient to take out; 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.

[0041] Before step S1, various metals are melted in a furnace to obtain molten metal with a perfect ratio. The molten metal with a perfect ratio is then poured in S4, and finally a complete gate valve is obtained through S5. This process can produce products with high molding quality.

[0042] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A gate valve body casting device, characterized in that: include: 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. A gate valve body casting device 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 gate valve body casting device 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 compacting plate 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 gate valve body casting device according to claim 3, characterized in that: The pressing plate (51) comprises a plurality of tamping plates (511) arranged in a rectangular array; the second driving member comprises a plurality of hydraulic cylinders (52) arranged on the machine body (1) in a rectangular array; the plurality of hydraulic rods correspond to the plurality of tamping plates (511) one by one; and the clearance holes (512) are provided on several of the tamping plates (511).

5. A gate valve body casting device according to claim 4, characterized in that: The machine body (1) is also provided with a lifting assembly (7) for driving the core box (2) to move up and down, the lifting assembly (7) being connected to the bottom plate (21), and the lifting assembly (7) can drive the core box (2) to descend rapidly.

6. A gate valve body casting device according to claim 2, characterized in that: The maximum diameter of the sand core column (4) is greater than the diameter of the suction cup (411).

7. A gate valve body casting device according to claim 6, characterized in that: A plurality of communication openings (412) are provided between the suction cup (411) and the air bag (41).

8. A gate valve production process, based on a gate valve body casting device according to any one of claims 1 to 7, comprising 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.

9. A gate valve, obtained by the gate valve production process according to claim 8, comprising the following components in terms of mass fraction: 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.

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