A method for preparing investment casting slurry and an automated shell-making production line for investment casting

Abstract

The present invention discloses a method for preparing investment casting slurry. S1: Mix silicon-based ceramic powders of different particle grades. Take fused quartz silica with a particle size of 100-500 nm, which accounts for 40%-45% of the total powder mass; silica with a particle size of 1-100 μm, which accounts for 20%-35% of the total powder mass; and silica with a particle size of 300-500 μm, which accounts for 10%-35% of the total powder mass. The present invention provides a method for preparing investment casting slurry and an automatic shell-making production line for investment casting. By using photocurable slurry, after sand spraying, UV light is irradiated through the gaps between the sand grains onto the slurry adhered to the investment mold, thereby curing the slurry. At the same time, the sand grains adhered to the surface of the slurry are also cured together, making the curing process of the entire sand shell simple and fast, improving the shell-making efficiency, and reducing the energy consumption of shell-making.

Description

Technical Field

[0001] The present invention relates to the technical field of automated shell making, in particular to a method for configuring investment casting slurry and an automated shell making production line for investment casting. Background Art

[0002] Investment casting, also known as lost-wax casting, requires repeated sand spraying on the surface of the wax mold at the initial stage of casting to form a complete sand shell. With the development of automation, robots as described in the patent with publication number CN113182497A are used to achieve the work of sticking slurry on the surface of the wax mold and sand spraying.

[0003] Existing slurries are solidified by drying, and the solidification speed limits the transfer speed of the sand mold. If it is not completely solidified after slurry dipping and sand spraying, it cannot be dipped and sand sprayed again. Therefore, in the shell making production line, the shell making speed completely depends on the solidification speed after slurry dipping and sand spraying.

[0004] At the same time, the existing solidification process requires a large amount of energy to accelerate its solidification.

[0005] Therefore, a slurry that can be quickly solidified with low energy consumption is needed. Summary of the Invention

[0006] Existing slurries have a long solidification time after slurry dipping and sand spraying on the wax mold, and at the same time, the energy consumption for their solidification is high.

[0007] The present invention provides a method for configuring investment casting slurry and an automated shell making production line for investment casting in view of the deficiencies in the prior art.

[0008] To solve the above technical problems, the present invention is solved by the following technical solutions: A method for configuring investment casting slurry:

[0009] S1: Mix silicon-based ceramic powders with different particle grades:

[0010] Take fused quartz silica with a particle size of 100 - 500 nm, and its mass ratio in the total powder is 40% - 45%;

[0011] Silica with a particle size of 1 - 100 μm, and its mass ratio in the total powder is 20% - 35%;

[0012] Silica with a particle size of 300 - 500 μm, and its mass ratio in the total powder is 10% - 35%.

[0013] S2: Mix a photoinitiator, a light absorber, a crosslinking agent, and a monomer, wherein the main monomer is 1,6 - hexanediol diacrylate.

[0014] S3: Take the silicon-based ceramic powder mixed in S1 and the mixture mixed in S2, and stir them using a blender.

[0015] S4: In the blender in S3, use different rotation speeds to stir the mixture into a viscous mixture, thereby obtaining a slurry.

[0016] Its beneficial effect is that the prepared slurry can be cured by UV light irradiation, and the silicon-based ceramic powder inside is cured simultaneously during the curing process.

[0017] In the above solution, preferably, the purity of the nano-scale and micro-scale silica in S1 is 99 wt%.

[0018] In the above solution, preferably, a mineralizer is added during the mixing and stirring process in S3 to adjust the viscosity of the slurry.

[0019] In the above solution, preferably, in S4, S41: The blender first runs at a rotation speed of 20 - 40 r / min for 1 - 10 min; S42: Runs at a rotation speed of 60 - 100 r / min for 5 - 15 min; S43: Runs at a rotation speed of 150 - 300 r / min for 15 - 20 min; S44: Runs at a rotation speed of 300 - 400 r / min for 2 - 20 min to obtain the slurry.

[0020] Its beneficial effect is that the stirring is more uniform, and the performance of the entire barrel of slurry after stirring remains consistent.

[0021] In the above solution, preferably, the stirring time in S41 is 5 - 8 min; in S44, the rotation speed is 350 - 380 r / min and it runs for 5 - 10 min.

[0022] The investment casting automatic shell-making production line includes a slurry preparation chamber. Inside the preparation chamber, there is a blender and a transfer cart for transporting the blender. The blender is used to stir the mixture into a slurry. There is a sand spraying production line, which includes multiple sand sprayers, robots, and an investment casting transfer line. There are blenders containing slurry placed around the sand sprayers. Investment castings are hung on the investment casting transfer line. The robot clamps and immerses the investment castings on the investment casting transfer line into the slurry in the blender, then transfers them to the sand sprayer for sand spraying, and then hangs and places them on the investment casting transfer line for transfer. There is a solidification chamber, and a UV light irradiation device is arranged inside the solidification chamber to accelerate the curing of the slurry with adhered sand.

[0023] Its beneficial effect is that by using a photocurable slurry, after sand spraying, by irradiating UV light, the UV light irradiates the slurry adhered to the investment casting from the gaps between the sand grains, thereby curing the slurry, and simultaneously curing the sand grains adhered to the surface of the slurry, making the curing process of the entire sand shell simple and fast.

[0024] In the above solution, preferably, the mixer located around the sand spraying machine rotates at a speed of 20 - 40 r / min to prevent the slurry from depositing.

[0025] In the above solution, preferably, after the robot immerses the investment casting in the mixer, it rotates 3 - 10 circles at a speed of 20 - 40 r / min, and then rotates 3 - 10 circles in the reverse direction. After the robot lifts the investment casting out of the mixer, it rotates 3 - 10 circles at a speed of 20 - 40 r / min, and then rotates 3 - 10 circles in the reverse direction.

[0026] In the above solution, preferably, the sand spraying production line 2 further includes a dust removal device for reducing the dust content around the sand spraying production line.

[0027] In the above solution, preferably, the dust removal device is connected to the inside of the sand spraying machine through a pipeline to reduce dust spillage during sand spraying.

[0028] The beneficial effects of the present invention are: a method for preparing investment casting slurry and an automated shell making production line for investment casting. The photocurable slurry is used, and after sand spraying, UV light is irradiated. The UV light irradiates the slurry adhered to the investment casting from the gaps between the sand grains, thereby curing the slurry. At the same time, the sand grains adhered to the surface of the slurry are also cured together, making the curing process of the entire sand shell simple and fast, improving the shell making efficiency, and reducing the energy consumption of shell making. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the production line of the present invention.

[0030] Figure 2 It is a partial schematic diagram of the present invention.

[0031] Figure 3 It is a cross-sectional view of the detection unit and the collection unit of the present invention.

[0032] Figure 4 It is a partially enlarged view of the concave inflatable part of the present invention.

[0033] Figure 5 It is a partially enlarged view within the cross-sectional plane of the spray channel of the present invention.

[0034] Figure 6 It is a partially enlarged view within the cross-sectional plane of the outflow pipe of the present invention.

[0035] Figure 7 It is a partially enlarged view of the joint between the collection unit and the base of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will be further described in detail below in conjunction with the drawings and the specific embodiments: Embodiment

[0037] SeeFigures 1-7 ,

[0038] A method for preparing investment casting slurry. S1: Take nano-scale and micro-scale silicon-based ceramic powders and mix them. Among them, the fused quartz silica with a particle size of 200 - 300 nm accounts for 40% - 45% of the total powder mass, the silica with a particle size of 50 - 80 μm accounts for 30% - 35% of the total powder mass, and the silica with a particle size of 300 - 400 μm accounts for 20% - 35% of the total powder mass. Mix them into a mixed silicon-based ceramic powder, and the purity of both nano-scale and micro-scale silica is 99 wt%.

[0039] S2: Take a photoinitiator, a light absorber, a crosslinking agent, and a monomer and mix them. Among them, the main monomer is 1,6 - hexanediol diacrylate, the crosslinking agent is ethoxylated pentaerythritol tetraacrylate (PPTTA), the photoinitiator is a mixture of benzoin dimethyl ether, 2,4,6 - trimethylbenzoyl diphenylphosphine oxide, triarylsulfonium salts, etc., and the light absorber is mainly phenyl salicylate.

[0040] S3: Take the silicon-based ceramic powder mixed in S1 and the mixture mixed in S2, and stir them using a blender. The blender first runs at a speed of 20 - 40 r / min for 5 - 8 min, then runs at a speed of 60 - 100 r / min for 5 - 15 min, then runs at a speed of 150 - 300 r / min for 15 - 20 min, and then runs at a speed of 350 - 380 r / min for 5 - 10 min to obtain the slurry. Then, stir at a speed of 20 - 40 r / min to prevent the slurry from depositing.

[0041] When putting them into the blender for stirring, a mineralizer also needs to be added. The mineralizer is a mixture of alumina and zirconia, which is used to adjust the viscosity of the slurry.

[0042] Among them, the silicon-based ceramic powder mixed in S1 accounts for 30% - 35% of the total mass of the slurry, the mineralizer accounts for 8% - 10% of the total mass of the slurry, the photoinitiator accounts for 4% - 5% of the total mass of the slurry, the light absorber accounts for 4% - 5% of the total mass of the slurry, the crosslinking agent accounts for 3% - 5% of the total mass of the slurry, the monomer accounts for 15% - 40% of the total mass of the slurry, and the mass ratio of the crosslinking agent to the monomer is (5 - 8):1.

[0043] The investment casting automatic shell-making production line includes a slurry preparation chamber 1, a sand spraying production line 2 and a solidification chamber. The preparation chamber 1 is equipped with a mixer 11 and a transfer vehicle 12. A manipulator or a feeding device puts the mixture into the mixer 11, and the mixer 11 starts to stir the mixture into slurry. When the slurry in the mixer 11 in the sand spraying production line 2 gives an alarm for insufficient amount, the mixer 11 that has completed stirring is moved to the sand spraying production line 2 by the transfer vehicle 12 to replace the mixer with an alarm for insufficient amount.

[0044] The sand spraying production line 2 includes a plurality of sand sprayers 21, robots 22 and an investment casting transfer line arranged in sequence. The investment casting transfer line is provided with an outlet at the position of each sand sprayer 21. The robot 22 takes the investment casting to be sand sprayed from the investment casting transfer line, immerses it in the slurry of the mixer 11, and the robot 22 controls the investment casting to rotate clockwise at a speed of 20 - 40 r / min for 3 - 5 circles, then rotate counterclockwise at the same speed for 3 - 5 circles, then lift the investment casting from the mixer 11 and keep it stationary for 30 - 90 S to let the excess slurry drip off, then rotate clockwise at a speed of 20 - 40 r / min for 3 - 5 circles again, then rotate counterclockwise at the same speed for 3 - 5 circles, and then send the investment casting into the sand sprayer 21 for sand spraying operation. After the sand spraying is completed, the investment casting is hung back on the investment casting transfer line, and the investment casting transfer line drives the investment casting after sand spraying into the solidification chamber. The solidification chamber is provided with a UV lighting device, and ultraviolet light irradiates the slurry through the gaps of the sand, so that the slurry is quickly solidified, thereby reducing the solidification time of the sand shell after sand spraying and improving the shell-making efficiency.

[0045] The sand spraying production line 2 is also equipped with a dust removal device, which is used to reduce the dust content around the sand spraying production line 2 and is connected to the inside of the sand sprayer 21 through a pipeline to reduce the dust spillage during sand spraying.

[0046] It also includes a detection unit 3 and a collection unit 4. The collection unit 4 is fixedly arranged on the side of the dust removal device through a fixed frame. The collection unit 4 includes a housing, a dust suction port 41 and a dust suction pipeline 42. One end of the dust suction pipeline 42 is connected to the dust suction pipe of the dust removal device through a pipeline, and the other end is connected to the dust suction port 41. Thus, when the dust removal device is working, the dust around the sand sprayer can be sucked into the dust removal device through the dust suction port 41, reducing the dust in the surrounding environment.

[0047] The detection unit 3 includes a dust detection component 31, a lifting device 32, a spraying device 33, and a concave inflatable component 34. The dust detection component 31 includes an inlet pipe 311, a laser dust detector 312, and an outlet pipe 315. The bottom of the outlet pipe 315 is communicated with the bottom of the inlet pipe 311. The concave inflatable component 34 is a hemispherical body that is concave upward and filled with a low-density gas, specifically including hydrogen and helium, thereby endowing the concave inflatable component 34 with the ability to suspend and rise in the air. The concave inflatable component 34 is fixedly connected to the upper end of the inlet pipe 311 through a fixing rod. A downward guiding cone 341 is provided at the center of the concave surface of the concave inflatable component 34, and the center of the guiding cone 341 is aligned with the inlet pipe 311. The upper end of the inlet pipe 311 is set as a tapered opening, so that the air introduced by the concave inflatable component 34 can be better introduced into the inlet pipe 311 and flow out from the outlet pipe 315.

[0048] The laser dust detector 312 is arranged in the inlet pipe 311. A flow pipe is arranged in the laser dust detector 312. The air flowing through the inlet pipe 311 enters the laser dust detector 312. The laser dust detector 312 can detect the dust content in the flowing air. In order to ensure the consistency in the dust detection process, it is necessary to control the consistency of the flow rate flowing to the laser dust detector 312, so as to ensure that the flow rate entering the laser dust detector 312 is consistent and ensure the detection result. Therefore, an adjusting plate 314 is arranged in the inlet pipe 311, and the adjusting plate 314 is located above the laser dust detector 312 and is used to adjust the air flow rate flowing to the laser dust detector 312.

[0049] The lifting device 32 includes a base 321, an elastic support member 322, and a pulling device 323. The dust detection component 31 and the spraying device 33 are arranged on the base 321. One end of the elastic support member 322 abuts against the base 321, and the other end abuts against the collection unit 4. The pulling device 323 includes a pull rope 3231 and a winding motor 3232. The winding motor 3232 is arranged on the collection unit 4. One end of the pull rope 3231 is connected to the center of the base 321, and the other end is connected to the winding motor 3232. The pull rope 3231 is located in the middle of the elastic support member 322, and the elastic support member 322 is a spring.

[0050] When the winding motor 3232 winds, the pull rope 3231 is wound on the winding disc, thereby pulling the base 321 to move downward. During the downward movement, the elastic support member 322 is compressed. When the winding motor 3232 releases, the base 321 rises under the action of the elastic support member 322. At the same time, when the base 321 rises to the highest point, the elastic support member 322 maintains a certain elastic force so that the base 321 will not sway left and right.

[0051] The spray device 33 includes a spray ring 331, a spray channel 332 communicating with the spray ring 331, an ultrasonic high-frequency oscillator 333, and a water storage chamber 334. The water storage chamber 334 is arranged on the base 321 and can store a certain amount of water inside. One end of the spray channel 332 is arranged inside the water storage chamber 334, and an access port 3321 is opened on the spray channel 332 at this end. A fan is arranged above the access port 3321 for introducing the air inside the water storage chamber 334 into the spray channel 332. The upper end of the spray channel 332 communicates with the spray ring 331. The spray ring 331 is provided with spray openings around it and is located above the concave inflatable member 34. The outflow pipe 315 is fixedly arranged on the spray ring 331, so that both the spray and the discharged inflowing air are located above the concave inflatable member 34.

[0052] When it is necessary to detect the dust in the surrounding environment, the winding motor 3232 first releases the pull rope 3231, and the elastic support member 322 drives the dust detection member 31 and the spray device 33 to rise to the highest point. At this time, the highest point is freely set according to the height of the site. After reaching the highest point, the winding motor 3232 starts to rotate, driving the dust detection member 31 and the spray device 33 to move downward. The concave inflatable member 34 guides the air collected in the cross-section into the access pipe 311, and the laser dust detector 312 detects the dust content of the inflowing air.

[0053] The ultrasonic high-frequency oscillator 333 adjusts the vibration frequency according to the detected dust content with reference to the parameters of the control system. When the dust content is high, the vibration frequency is high, and thus more water mist is generated and sprayed outwards from the spray ring 331. When the dust content is high, the rotational speed of the winding motor 3232 slows down, so that the dust detection member 31 and the spray device 33 stay in this area for a longer time, and the spray device 33 sprays more water mist around, causing the dust in the surrounding air to agglomerate and fall downward.

[0054] When the rotational speed of the winding motor 3232 slows down, the air flow rate introduced into the access pipe 311 decreases, and thus the flow rate of the air flowing through the laser dust detector 312 slows down. To ensure the accuracy of the detection, the control regulating plate 314 is controlled to extend, and the opening above the laser dust detector 312 decreases, so that the air flow rate increases to the previous flow rate, and thus the value measured by the laser dust detector 312 remains accurate.

[0055] A first channel 313 is formed in the inlet pipe 311. One end of the first channel 313 communicates with the inlet pipe 311, and the other end communicates with the water storage chamber 334. Thus, when the fan at the inlet 3321 rotates, the air in the water storage chamber 334 can be blown into the spray channel 332. At the same time, when the adjusting plate 314 extends forward, part of the air entering the inlet pipe 311 is blocked by the adjusting plate 314, and then flows back into the first channel 313 and then into the spray channel 332. Thus, when the winding motor 3232 decelerates, some air enters the spray channel 332, and more water mist is sprayed out at the spray ring 331.

[0056] At the same time when the winding motor 3232 decelerates, the oscillation frequency of the ultrasonic high-frequency oscillator 333 increases, thus generating more water mist. As a result, the water mist content in the air flow sprayed out by the spray ring 331 is higher, causing more dust to agglomerate and fall downward, thereby achieving a better dust removal effect.

[0057] The dust suction port 41 is located below the detection unit 3. After the spray device 33 sprays water mist, the dust agglomerates and falls downward, and is sucked into the dust suction pipe 42 by the dust suction port 41, thereby playing a role in dust removal. At this time, the air sucked at the dust suction port 41 has a higher humidity due to the effect of spraying. If it is directly sucked into the dust removal device, it may adhere to the dust removal bag in the dust removal device, thereby reducing the dust removal effect of the dust removal device. Therefore, a condensation device is provided in the dust suction pipe 42. The air sucked by the dust suction port 41 passes through the condensation device and then is sucked into the dust removal device, thereby protecting the dust removal device.

[0058] A conductive ring 3211 and a water inlet channel 3212 are provided on the base 321. A charging slot 43 matching the conductive ring 3211 and a water replenishing channel 44 adapted to the water inlet channel 3212 are provided on the collection unit 4. The winding motor 3232 winds the pull rope 3231 until the base 321 presses against the collection unit 4. The conductive ring 3211 is inserted into the charging slot 43 to charge the battery power source provided on the base 321 for supplying power to the ultrasonic high-frequency oscillator 333 and the laser dust detector 312. At the same time, the water replenishing channel 44 communicates with the water inlet channel 3212 to replenish water to the water storage chamber 334.

[0059] Its working principle or usage method is as follows:

[0060] The detection work can be started through timing control, and the detection unit 3 and the collection unit 4 are controlled by the central control unit in the production line, and the detection work is automatically started after the sand spraying machine runs for a set time each time.

[0061] When starting the detection work, the winding motor 3232 releases the brake. Then, the base 321 rises upward under the action of the elastic support 322. The upward movement of the base 321 drives the dust detection part 31 and the spray device 33 to move upward together to the highest point.

[0062] After reaching the top, the winding motor 3232 starts to wind the pulling rope 3231, which then drives the base 321 to move downward. During the downward movement, it drives the dust detection part 31 and the spray device 33 to move downward, and the concave inflatable part 34 also descends together. Then, the air converged in the concave surface is introduced into the access pipe 311 through the guiding cone 341, flows through the laser dust detector 312, and is discharged from the upper end of the outflow pipe 315. The laser dust detector 312 detects the dust in the flowing air.

[0063] The rotation speed of the winding motor 3232 is controlled by the value detected by the laser dust detector 312. The greater the dust content, the slower the rotation speed of the winding motor 3232. At the same time, the vibration frequency of the ultrasonic high-frequency oscillator 333 increases, so that the spray device 33 sprays more water mist per unit height, causing more dust to agglomerate. The concave inflatable part 34 is a hemispherical body sunken upward. Therefore, even if the dust agglomerates and falls, it falls on the spherical surface of the concave inflatable part 34 and will not fall into the space below the concave inflatable part 34, thus not affecting the subsequent detection results.

[0064] At the same time, due to the slowdown of the rotation speed of the winding motor 3232, the air flow rate through the laser dust detector 312 slows down. To ensure the detection result, through the electric control adjusting plate 314, a flow rate sensor is set on the laser dust detector 312. By changing the protruding position of the adjusting plate 314, the size of the channel opening in front of the adjusting plate 314 is changed, and thus the air flow rate through the channel opening is changed to keep the air flow rate through the laser dust detector 312 consistent.

[0065] Part of the air blocked and refluxed by the adjusting plate 314 flows into the water storage chamber 334 from the first channel 313, which increases the air entering the access port 3321. The spray ring 331 sprays more air, further increasing the spray quantity and thus enhancing the dust reduction effect.

[0066] The dust agglomerates fall downward and are sucked into the dust suction pipe 42 through the dust suction port 41, thus playing a role in dust removal.

[0067] When the winding motor 3232 winds the pulling rope 3231 until the base 321 touches the collection unit 4, the winding motor 3232 stops rotating and maintains the braking state. At this time, the conductive ring 3211 is inserted into the charging slot to charge the power supply set on the base 321. At the same time, the water replenishing channel is communicated with the water inlet channel 3212 to replenish water to the water storage chamber 334, making preparations for the next detection.

[0068] Meanwhile, a switch device is provided on the dust suction pipe 42. The switch device is used to open or block the dust suction pipe 42. At the beginning of the detection, the switch device is opened, and then the dust suction operation is carried out. After the winding motor 3232 stops, the delay closing time of the switch device is controlled according to the winding time of the winding motor 3232. The longer the running time of the winding motor 3232, the longer the delay closing time, so that more agglomerated dust is sucked in. Embodiment

[0069] The difference from the first embodiment lies in the installation position of the collection unit 4, which is the same as others. See Figures 1-7 , and the collection unit 4 can also be independently installed on the ground through a bracket and is located around the sand spraying machine. Embodiment

[0070] The difference from the first embodiment lies in the installation position of the collection unit 4 and the dust suction method of the collection unit 4, which is the same as others. See Figures 1-7 , the detection unit 3 is installed on the collection unit 4, the collection unit 4 is installed on the AGV cart, the rear end of the dust suction pipe 42 of the collection unit 4 is connected to the vacuum cleaner, and the AGV cart moves freely on the preset track in the site and stops at a random position on the track, and then starts the detection and dust removal work.

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An automated shell production line for investment casting, characterized in that: Slurry preparation method S1: Mix silicon-based ceramic powders of different particle sizes: Take fused silica with a particle size of 100-500 nm, which accounts for 40%-45% of the total powder mass; Silicon dioxide with a particle size of 1-100 μm, accounting for 20%-35% of the total powder mass; Silicon dioxide with a particle size of 300-500 μm, accounting for 10%-35% of the total powder mass; S2: mixing a photoinitiator, a light absorber, a crosslinking agent and a monomer, wherein the main monomer is 1,6-hexanediol diacrylate; S3: taking a mixture of the silicon-based ceramic powder mixed in S1 and the mixture of S2, and stirring them using a stirrer; S4: The mixer in S3 stirs the mixture into a viscous mixture using different rotation speeds, thereby obtaining a slurry; The production line includes a slurry preparation room, wherein the preparation room includes a mixer and a transfer vehicle for transporting the mixer, and the mixer is used to mix the mixture into slurry; Sand spraying line, which includes multiple sand spraying machines, robots and investment mold transfer lines. A mixer with slurry is placed around the sand spraying machine, and investment molds are hung on the investment mold transfer line. The robot clamps the mold on the mold flow line and immerses it into the slurry in the mixer. After transferring it to the sand spraying machine for sand spraying, it is hung on the mold flow line for circulation. A solidification chamber, in which a UV light device is provided to accelerate the solidification of the slurry with sand and gravel; It also includes a detection unit, which includes a dust detection part, a lifting device, a spray device and a concave inflatable part. The dust detection part includes an inlet pipe, a laser dust monitor and an outflow pipe. The bottom of the outflow pipe is connected to the bottom of the inlet pipe. The concave inflatable part is an upwardly concave hemispherical body filled with low-density gas. The concave inflatable part is fixedly connected to the upper end of the inlet pipe through a fixing rod. A downward guiding cone is arranged at the center of the concave surface of the concave inflatable part. The center of the guiding cone is aligned with the inlet pipe, and the upper end of the inlet pipe is arranged with a cone mouth, so that the air introduced by the concave inflatable part can be better introduced into the inlet pipe and flow out from the outflow pipe. The lifting device includes a base, an elastic support member and a pulling device. The dust detection member and the spray device are arranged on the base. One end of the elastic support member touches the base, and the other end touches the collection unit. The pulling device includes a pull rope and a winding motor. The winding motor is arranged on the collection unit. One end of the pull rope is connected to the center of the base, and the other end is connected to the winding motor. The pull rope is located in the middle of the elastic support member, and the elastic support member is a spring. The spray device includes a spray ring, a spray channel connected to the spray ring, an ultrasonic high-frequency oscillator and a water storage chamber. The water storage chamber is arranged on the base and can store water inside. One end of the spray channel is arranged in the water storage chamber, and a through inlet is provided on the spray channel at this end. A fan is provided above the through inlet for passing the air in the water storage chamber into the spray channel. The upper end of the spray channel is connected to the spray ring. A spray port is provided around the spray ring and is located above the concave inflatable member. The outflow pipe is fixedly arranged on the spray ring, so that the spray and the inflowing air are discharged above the concave inflatable member. The laser dust monitor is arranged in the inlet pipe, and a flow tube is arranged in the laser dust monitor. The air flowing through the inlet pipe enters the laser dust monitor, and the laser dust monitor can detect the dust content in the air flowing through.

2. The investment casting automated shell production line according to claim 1, characterized in that: The mixer located around the sand spraying machine has a rotation speed of 20-40r / min to prevent slurry from settling.

3. The investment casting automated shell production line according to claim 2, characterized in that: After the robot immerses the melt in the mixer, it rotates at a speed of 20-40 r / min for 3-10 turns, and then rotates in the opposite direction for 3-10 turns; After the robot lifts the melt from the mixer, it rotates it at a speed of 20-40r / min for 3-10 circles, and then rotates it in the opposite direction for 3-10 circles.

4. The investment casting automated shell production line according to claim 1, characterized in that: The sand spraying line also includes a dust removal device for reducing the dust content around the sand spraying line.

5. The investment casting automated shell production line according to claim 4, characterized in that: The dust removal device is connected to the inside of the sand shower machine through a pipeline, so as to reduce dust overflow when the sand shower is being performed.

Images