Nickel-aluminum bronze impeller sand mold casting bottom pouring process

Abstract

The invention discloses a nickel-aluminum bronze impeller sand mold casting bottom pouring process, and relates to the technical field of casting, and the nickel-aluminum bronze impeller sand mold casting bottom pouring process comprises the following steps: S1, alloy smelting: weighing 87-90 parts by weight of Cu, 8-10 parts by weight of Al, 3-5 parts by weight of Fe, 3-5 parts by weight of Ni and 1-2 parts by weight of Mn, and melting in smelting equipment; s2, a casting system is designed, specifically, computer simulation software is used for conducting casting system design, and the positions and sizes of a sprue, a riser and an ingate are optimized; s3, casting mold preparation: manufacturing a casting mold, and carrying out sand mold modeling and mold closing; s4, casting is conducted, specifically, molten metal is fed into a casting ladle and slowly injected from a pouring gate in the bottom of a casting mold; s5, solidifying and cooling: controlling the casting to be gradually cooled and solidified from the bottom to the top; s6, post-treatment is conducted, specifically, a casting in the casting mold is demolded and cleaned, and a sprue and a dead head are removed; by optimizing a casting system and cooling conditions, the defects of internal air holes, inclusions, shrinkage cavities, shrinkage porosity and the like are remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of casting, in particular to a bottom pouring process for sand casting of a nickel-aluminum-bronze impeller. Background Art

[0002] Nickel aluminum bronze is widely used in key components in the fields of shipbuilding, chemical industry, power, etc., especially impellers, due to its excellent corrosion resistance, wear resistance and good mechanical properties. Impellers are core components of fluid machinery such as pumps and fans, and their performance directly affects the operating efficiency and service life of the entire equipment.

[0003] However, traditional casting processes have many problems when producing nickel-aluminum bronze impellers, such as many internal defects and unstable mechanical properties. It is urgent to improve product quality and production efficiency through technological innovation. Summary of the invention

[0004] The object of the present invention is to provide a nickel-aluminum bronze impeller sand casting bottom pouring process to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A nickel-aluminum bronze impeller sand casting bottom pouring process comprises the following steps: S1. Alloy smelting: weigh 87-90 parts of Cu, 8-10 parts of Al, 3-5 parts of Fe, 3-5 parts of Ni, and 1-2 parts of Mn by weight, and put them into a smelting equipment for melting; S2. Casting system design Use computer simulation software to design the casting system and optimize the position and size of the gate, riser and ingates; S3, mold preparation, making mold, sand mold shaping and box assembly; S4, casting, sending the molten metal into the ladle and slowly pouring it from the gate at the bottom of the mold; S5, solidification cooling, control the casting to gradually cool and solidify from the bottom to the top; S6. Post-processing: demoulding and cleaning the casting in the mold, and removing the gate and riser.

[0006] Preferably, the sand mold preparation material is silica sand or chromite sand.

[0007] Preferably, the surface of the demoulding casting is heat treated.

[0008] Preferably, the casting after heat treatment is subjected to non-destructive testing using ultrasound or X-rays.

[0009] Preferably, the equipment used in the above process includes a medium frequency induction furnace, a casting cooling device, a demolding and cleaning device, and a cutting device. The casting cooling device includes a base, a mounting frame is provided on the base, a molten metal casting mechanism is provided on the mounting frame, a rotating disk is rotatably mounted on the base, a lifting mechanism is provided at the center of the rotating disk, the lifting mechanism drives the rotating disk to move up and down, a plurality of groups of casting mechanisms are evenly arranged on the edge of the rotating disk, the molten metal casting mechanism is docked with the plurality of groups of the casting mechanisms in turn for docking and casting, a cooling and cutting mechanism is provided at the mounting position of the casting mechanism and the rotating disk, and a cooling mechanism is provided inside the casting mechanism.

[0010] Preferably, the molten metal casting mechanism includes a pressurizer arranged on a mounting frame, one end of the pressurizer is connected to an inert gas tank, the other end of the pressurizer is connected to a heating cylinder, the heating cylinder is closed, a crucible is placed in the heating cylinder, an electric heating wire is arranged on the outside of the crucible, a liquid feeding pipe is fixedly installed on the side wall of the heating cylinder, one end of the liquid feeding pipe passes through the heating cylinder and the crucible and extends to the bottom of the crucible, and the other end of the liquid feeding pipe is butt-jointed with the bottom of the casting mechanism.

[0011] Preferably, the casting mechanism includes a model frame plugged into the edge of the rotating disk, the model frame is arranged in a two-petal type, a limiting ring is provided at the bottom of the model frame, the model frame is limitedly plugged between the limiting ring and the rotating disk, a docking pipe is provided at the bottom of the model frame, the docking pipe is docked with the liquid feeding pipe, an upper mold frame and a lower mold frame are placed in the model frame, the sand mold between the upper mold frame and the lower mold frame constitutes a casting cavity, an installation groove is provided between the upper mold frame, the lower mold frame and the model frame, a spiral tube is installed in the installation groove, the bottom of the spiral tube passes through the model frame and is connected to a vertical cooling pipe, the upper end of the spiral tube passes through the model frame and is connected to a return water pipe, and the vertical cooling pipe is connected to the cooling mechanism.

[0012] Preferably, the cooling mechanism comprises a fixedly mounted mounting frame, on which a water tank 1 is arranged, and the water tank 1 is connected to a filling pipe, and the filling pipe is aligned with the top of the vertical cooling pipe.

[0013] Preferably, a center column is provided on the base, the lifting mechanism is connected to the top of the center column, the rotating disk is connected to the lifting mechanism, the lifting mechanism comprises a mounting plate 1 arranged on the center column, a plurality of groups of connecting columns are evenly arranged on the mounting plate 1, a mounting plate 2 is provided on the top of the connecting column, a motor 2 is fixedly provided on the mounting plate 2, the motor 2 is connected to an output shaft, the output shaft is connected to a worm, a rotating mounting part is provided on the output shaft, a mounting ring is provided on the rotating mounting part for limiting rotation, a connecting frame is evenly provided in the circumference of the mounting ring, a worm gear is rotatably mounted on the connecting frame, the worm gear and the worm gear are meshed with each other, a mounting cylinder is provided at the upper end of the rotating disk, the mounting cylinder is sleeved on the outer side of the worm gear, a vertical rack is provided on the inner side of the mounting cylinder, the vertical rack and the worm gear are meshed with each other, and the mounting frame is fixedly connected to the edge of the mounting plate 2.

[0014] Preferably, the cooling cut-off mechanism includes a water tank 2, which is fixedly mounted on the edge of a mounting plate 2, the water tank 2 is connected to a telescopic tube, the telescopic tube is connected to a water outlet ball head, receiving grooves are evenly arranged on the rotating plate corresponding to the casting mechanism, the water outlet ball head and the receiving groove cooperate with each other, a guide groove 1 is arranged between the receiving groove and the plug-in part of the model frame, an annular groove 1 is arranged on the outer circle of the plug-in part of the model frame, a plurality of groups of vertical grooves are evenly arranged on the inner circle of the annular groove 1, an annular groove 2 is arranged at the bottom of the vertical groove, the annular groove 2 is connected to a guide groove 2, the guide groove 2 is arranged on the inner side of the rotating plate and connected to the bottom of the rotating plate.

[0015] Preferably, one end of the guide groove 2 located at the bottom of the rotating disk is connected to a receiving tube, the receiving tube is connected to an annular tube, a drain pipe is provided at the bottom of the annular tube, a water collecting groove is provided on the base, and the drain pipe is directly opposite to the water collecting groove.

[0016] A fixing frame is arranged on the central column, a motor 1 is installed on the fixing frame, a driving gear is connected to the motor 1, a driven gear is arranged at the bottom of the rotating disk, the central column passes through the center of the driven gear and is rotatably installed between the rotating disk, and the driving gear and the driven gear are meshed with each other.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The molten metal is delivered to the mold mechanism through the molten metal casting mechanism. After the filling and casting of the mold mechanism is completed, the bottom of the mold mechanism is cooled and cut off in combination with the cooling and cutting mechanism. Then, the rotating disk is raised by the lifting mechanism to separate the mold mechanism from the molten metal casting mechanism, and the rotating disk is driven to rotate to the next station. The mold mechanism is cooled in combination with the cooling mechanism, and a new group of mold mechanisms is cast while cooling.

[0018] (2) Inert gas is injected into the heating cylinder of the pressurizer box, and the gas pressure is used to squeeze the molten metal in the crucible into the liquid delivery pipe, and then enter the casting mechanism for casting. In order to ensure that the molten metal in the liquid delivery pipe and the crucible remains in liquid state, electric heating wire 1 and electric heating wire 2 are respectively set to heat the entire casting process to prevent the cooling and solidification of the molten metal from affecting the transportation of the molten metal.

[0019] (3) The upper mold frame and the lower mold frame are positioned and installed by buckling the two-petal model frame together. At the same time, a limit ring is set at the bottom of the model frame, and it is plugged into the rotating disk in combination with the limit ring. An installation groove is set between the upper mold frame, the lower mold frame and the model frame to install the spiral tube. After the casting is completed, cooling water is injected into the spiral tube to accelerate the cooling of the casting. During cooling, cooling water is injected into the bottom of the spiral tube through the vertical cooling pipe, and the cooling water flows out from the return pipe at the upper end of the spiral tube.

[0020] (4) After the casting mechanism completes the casting of molten metal, in order to facilitate the rapid casting operation of the next casting mechanism, an annular groove 1 is set at the plug-in position of the model frame, and cooling water is injected into the guide groove 1 in combination with the water tank 2 and the water outlet ball head. The cooling water enters the annular groove 1, the vertical groove, the annular groove 2, and the guide groove 2 along the guide groove 1, thereby rapidly cooling the plug-in position of the model frame, so that the molten metal in the corresponding position inside the lower mold frame is rapidly cooled and solidified. Subsequently, the lifting mechanism can be combined to drive the rotating disk to rise, so that the casting mechanism is separated from the liquid feeding pipe, and the casting operation of the next group of casting mechanisms is carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0022] Figure 2 It is a schematic diagram of the overall structure of the casting cooling device in the present invention.

[0023] Figure 3 It is a schematic diagram of the installation structure of the heating cylinder in the present invention.

[0024] Figure 4 It is a schematic diagram of the external structure of the casting mechanism in the present invention.

[0025] Figure 5 It is a schematic diagram of the internal structure of the model frame in the present invention.

[0026] Figure 6 It is a schematic diagram of the cutaway structure of the upper mold frame and the lower mold frame in the present invention.

[0027] Figure 7 It is a schematic diagram of the bottom structure of the rotating disk in the present invention.

[0028] Figure 8It is a driving schematic diagram of the rotating disk in the present invention.

[0029] Fig. 9 It is a schematic diagram of the installation of water tank 1 in the cooling mechanism of the present invention.

[0030] Fig.10 It is a schematic diagram of the installation of the lifting mechanism in the present invention.

[0031] Fig.11 It is a schematic diagram of the internal structure of the lifting mechanism in the present invention.

[0032] Fig.12 It is a schematic diagram of the structure of the cooling and cutting mechanism in the present invention.

[0033] Fig.13 It is the installation schematic diagram of the water tank 2 in the present invention.

[0034] In the figure: 1, base; 2, mounting frame; 20, heating cylinder; 21, pressurizer; 22, crucible; 23, electric heating wire 1; 24, liquid feeding pipe; 25, electric heating wire 2; 3, casting mechanism; 30, model frame; 31, upper mold frame; 32, limit ring; 33, butt pipe; 34, lower mold frame; 35, spiral pipe; 350, mounting groove; 36, vertical cooling pipe; 37, return pipe; 4, rotating disk; 40, center column; 41, fixed frame; 42, motor 1; 43, driving gear; 44, driven gear; 5, lifting mechanism; 50, mounting cylinder; 51, mounting disk 1; 52, Connecting column; 53, mounting plate 2; 54, motor 2; 55, worm; 56, rotating mounting portion; 57, mounting ring; 58, connecting frame; 59, worm gear; 510, vertical rack; 6, cooling cut-off mechanism; 60, receiving groove; 61, guide groove 1; 62, annular groove 1; 63, vertical groove; 64, annular groove 2; 65, guide groove 2; 66, water tank 2; 67, telescopic tube; 68, water outlet ball head; 7, cooling mechanism; 70, receiving tube; 71, annular tube; 72, drain pipe; 73, water collecting groove; 74, mounting frame; 75, water tank 1; 76, filling pipe. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0036] like Figure 1 As shown, a nickel aluminum bronze impeller sand casting bottom pouring process comprises the following steps: S1. Alloy smelting: weigh 87-90 parts of Cu, 8-10 parts of Al, 3-5 parts of Fe, 3-5 parts of Ni, and 1-2 parts of Mn by weight, and put them into a smelting equipment for melting; S2. Casting system design: Use computer simulation software (such as ProCAST) to design the casting system, optimize the position and size of the gate, riser and ingates, ensure that the molten metal rises smoothly from the bottom, and reduce turbulence and air entrainment; S3, mold preparation, making mold, sand mold shaping and box assembly; S4, casting, the molten metal is sent into the ladle, slowly injected from the gate at the bottom of the mold, and gradually fills the mold by rising, reducing the formation of pores and inclusions. At the same time, a reasonable cooling channel is designed to ensure uniform temperature distribution in the mold to avoid local overheating and cold shut; S5, solidification cooling, control the casting to gradually cool and solidify from the bottom to the top; S6. Post-processing: demoulding and cleaning the casting in the mold, and removing the gate and riser.

[0037] Preferably, the sand mold preparation material is silica sand or chromite sand.

[0038] Preferably, the surface of the demoulding casting is heat treated.

[0039] Preferably, the casting after heat treatment is subjected to non-destructive testing using ultrasound or X-rays.

[0040] Further, such as Figure 2 As shown, the equipment used in the above process includes a medium frequency induction furnace, a casting cooling device, a demoulding cleaning device and a cutting device. The casting cooling device includes a base 1, a mounting frame 2 is arranged on the base 1, a molten metal casting mechanism is arranged on the mounting frame 2, a rotating disk 4 is rotatably mounted on the base 1, a lifting mechanism 5 is arranged at the center of the rotating disk 4, the lifting mechanism 5 drives the rotating disk 4 to move up and down, a plurality of groups of casting mechanisms 3 are evenly arranged on the edge of the rotating disk 4, the molten metal casting mechanism is in turn docked with the plurality of groups of the casting mechanisms 3 for casting, a cooling and cutting mechanism 6 is arranged at the mounting position of the casting mechanism 3 and the rotating disk 4, and a cooling mechanism 7 is arranged in the casting mechanism 3.

[0041] Specifically, the molten metal is delivered to the mold mechanism 3 through the molten metal casting mechanism. After the filling and casting of the mold mechanism 3 is completed, the bottom of the mold mechanism 3 is cooled and cut off in combination with the cooling and cutting mechanism 6. Then, the rotating disk 4 is raised by the lifting mechanism 5 to separate the mold mechanism 3 from the molten metal casting mechanism, and the rotating disk 4 is driven to rotate to the next station. The mold mechanism 3 is cooled in combination with the cooling mechanism 7, and a new group of mold mechanisms 3 is cast while cooling.

[0042] Further, such as Figure 3As shown, the molten metal casting mechanism includes a pressurizer 21 arranged on the mounting frame 2, one end of the pressurizer 21 is connected to an inert gas tank, the other end of the pressurizer 21 is connected to a heating cylinder 20, the heating cylinder 20 is closed, a crucible 22 is placed in the heating cylinder 20, an electric heating wire 23 is arranged on the outside of the crucible 22, a liquid feeding pipe 24 is fixedly installed on the side wall of the heating cylinder 20, one end of the liquid feeding pipe 24 passes through the heating cylinder 20 and the crucible 22 and extends to the bottom of the crucible 22, and the other end of the liquid feeding pipe 24 is connected to the bottom of the casting mechanism 3.

[0043] Specifically, inert gas is injected into the pressurizer 21 and the heating cylinder 20, and the molten metal in the crucible 22 is squeezed into the liquid feeding pipe 24 by the gas pressure, so as to enter the casting mechanism 3 for casting. In order to ensure that the molten metal in the liquid feeding pipe 24 and the crucible 22 remains in liquid state, electric heating wire 1 23 and electric heating wire 2 25 are respectively provided to heat the whole casting process to prevent the cooling and solidification of the molten metal from affecting the transportation of the molten metal.

[0044] Further, such as Figure 4 , Figure 5 , Figure 6 As shown, the casting mechanism 3 includes a model frame 30 plugged into the edge of the rotating disk 4, the model frame 30 is arranged in a two-petal type, a limiting ring 32 is arranged at the bottom of the model frame 30, the model frame 30 is limitedly plugged between the limiting ring 32 and the rotating disk 4, a docking pipe 33 is arranged at the bottom of the model frame 30, the docking pipe 33 is docked with the liquid feeding pipe 24, an upper mold frame 31 and a lower mold frame 34 are placed in the model frame 30, the sand mold between the upper mold frame 31 and the lower mold frame 34 constitutes a casting cavity, an installation groove 350 is arranged between the upper mold frame 31, the lower mold frame 34 and the model frame 30, a spiral tube 35 is installed in the installation groove 350, the bottom of the spiral tube 35 passes through the model frame 30 and is connected to a vertical cooling pipe 36, the upper end of the spiral tube 35 passes through the model frame 30 and is connected to a return water pipe 37, and the vertical cooling pipe 36 is connected to the cooling mechanism 7.

[0045] Specifically, the upper mold frame 31 and the lower mold frame 34 are positioned and installed by buckling the two-petal model frame 30 together. At the same time, a limit ring 32 is set at the bottom of the model frame 30, and the limit ring 32 is plugged into the rotating disk 4. An installation groove 350 is set between the upper mold frame 31, the lower mold frame 34 and the model frame 30 to install the spiral tube 35. After the casting is completed, cooling water is injected into the spiral tube 35 to accelerate the cooling of the casting. During cooling, cooling water is injected into the bottom of the spiral tube 35 through the vertical cooling pipe 36, and the cooling water flows out from the return pipe 37 at the upper end of the spiral tube 35.

[0046] Further, such as Figure 5 , Fig. 9 As shown, the cooling mechanism 7 includes a fixed mounting frame 74, on which a water tank 75 is provided. The water tank 75 is connected to a filling pipe 76, and the filling pipe 76 is aligned with the top of the vertical cooling pipe 36.

[0047] Further, such as Figure 8 , Fig.10 , Fig.11 As shown, the base 1 is provided with a central column 40, the lifting mechanism 5 is connected to the top of the central column 40, the rotating disk 4 is connected to the lifting mechanism 5, the lifting mechanism 5 includes a mounting plate 1 51 provided on the central column 40, a plurality of groups of connecting columns 52 are evenly arranged on the mounting plate 1 51, a mounting plate 2 53 is provided on the top of the connecting column 52, a motor 2 54 is fixedly provided on the mounting plate 2 53, the motor 2 54 is connected to an output shaft, the output shaft is connected to a worm 55, and a rotating mounting portion 5 is provided on the output shaft. 6. The rotating mounting portion 56 is provided with a mounting ring 57 for limited rotation, and a connecting frame 58 is evenly provided around the circumference of the mounting ring 57. A worm gear 59 is rotatably mounted on the connecting frame 58, and the worm gear 59 and the worm 55 are meshed with each other. A mounting cylinder 50 is provided at the upper end of the rotating disk 4, and the mounting cylinder 50 is sleeved on the outer side of the worm gear 59. A vertical rack 510 is provided on the inner side of the mounting cylinder 50, and the vertical rack 510 and the worm gear 59 are meshed with each other. The mounting frame 74 is fixedly connected to the edge of the mounting disk 2 53.

[0048] Specifically, after the casting is completed, the casting mechanism 3 needs to be separated from the liquid delivery pipe 24 to carry out the casting operation of the next group of casting mechanisms 3. The second motor 54 is fixedly installed by the first mounting plate 51 and the second mounting plate 53. When the second motor 54 drives the worm 55 to rotate, the worm gear 59 evenly arranged in the axial direction rotates. When the worm gear 59 rotates, it meshes with the vertical rack 510 inside the mounting cylinder 50, thereby driving the mounting cylinder 50 and the rotating disk 4 to perform lifting and lowering movements.

[0049] Further, such as Fig.12 , Fig.13As shown, the cooling cut-off mechanism 6 includes a water tank 66, which is fixedly mounted on the edge of the mounting plate 53, and the water tank 66 is connected to a telescopic tube 67, and the telescopic tube 67 is connected to a water outlet ball head 68. The rotating disk 4 is evenly provided with receiving grooves 60 corresponding to the casting mechanism 3, and the water outlet ball head 68 cooperates with the receiving groove 60. A guide groove 61 is provided between the receiving groove 60 and the plug-in part of the model frame 30, and an annular groove 62 is provided on the outer ring of the plug-in part of the model frame 30, and a plurality of groups of vertical grooves 63 are evenly provided on the inner ring of the annular groove 62. The bottom of the vertical groove 63 is provided with an annular groove 64, and the annular groove 64 is connected to a guide groove 65. The guide groove 65 is provided on the inner side of the rotating disk 4 and connected to the bottom of the rotating disk 4.

[0050] Specifically, after the casting mechanism 3 completes the casting of the molten metal, in order to facilitate the rapid casting operation of the next casting mechanism 3, an annular groove 62 is set at the plug-in position of the model frame 30, and cooling water is injected into the guide groove 61 in combination with the water tank 66 and the water outlet ball head 68. The cooling water enters the annular groove 62, the vertical groove 63, the annular groove 64, and the guide groove 65 along the guide groove 61, thereby quickly cooling the plug-in position of the model frame 30, so that the molten metal at the corresponding position inside the lower mold frame 34 is quickly cooled and solidified, and then the lifting mechanism 5 can be combined to drive the rotating disk 4 to rise, so that the casting mechanism 3 is separated from the liquid feeding pipe 24, and the casting operation of the next group of casting mechanisms 3 is carried out.

[0051] Further, such as Figure 8 , Fig.13 As shown, the guide groove 2 65 is located at one end of the bottom of the rotating disk 4 and is connected to a receiving tube 70, and the receiving tube 70 is connected to an annular tube 71, and a drain pipe 72 is provided at the bottom of the annular tube 71, and a water collecting groove 73 is provided on the base 1, and the drain pipe 72 is directly opposite to the water collecting groove 73.

[0052] Specifically, the guide groove 65 is connected to a receiving pipe 70 and an annular pipe 71. After the cooling water enters the annular pipe 71, it is guided into the water collecting groove 73 by the drainage pipe 72 to prevent the cooling water from dispersing and flowing.

[0053] It should be noted that the water tank 75 in the cooling mechanism 7 injects the cooling water into the vertical cooling pipe 36 and after spiral cooling in the casting mechanism 3, it is introduced into the guide groove 61 through the return pipe 37. The return pipe 37 is opposite to the guide groove 61, and also enters the water collecting groove 73 through the guide groove 2 65 and the receiving pipe 70 to collect the cooling water.

[0054] Further, such as Figure 8As shown, a fixing frame 41 is provided on the central column 40, a motor 42 is installed on the fixing frame 41, the motor 42 is connected to a driving gear 43, a driven gear 44 is provided at the bottom of the rotating disk 4, the central column 40 passes through the center of the driven gear 44 and is rotatably installed between the rotating disk 4, and the driving gear 43 and the driven gear 44 are meshed with each other.

[0055] The working principle of the embodiment of the present invention is: like Figure 1-Figure 13As shown, the molten metal is sent to the mold mechanism 3 through the molten metal casting mechanism. After the filling and casting of the mold mechanism 3 is completed, the bottom of the mold mechanism 3 is cooled and cut off in combination with the cooling and cutting mechanism 6. Then, the lifting mechanism 5 controls the rotary disk 4 to rise, so that the mold mechanism 3 is separated from the molten metal casting mechanism, and the rotary disk 4 is driven to rotate to the next station. The mold mechanism 3 is cooled in combination with the cooling mechanism 7, and a new group of mold mechanisms 3 are cast while cooling. Inert gas is injected into the heating cylinder 20 through the pressurizer 21, and the molten metal in the crucible 22 is squeezed into the liquid feeding pipe 24 by gas pressure, so as to enter the mold mechanism 3 for casting. In order to ensure that the molten metal in the liquid feeding pipe 24 and the crucible 22 remains in liquid state, electric heating wire 1 23 and electric heating wire 2 25 are respectively set to heat in the whole process of casting to prevent the cooling and solidification of the molten metal from affecting the transportation of the molten metal. The upper mold frame 31 and the lower mold frame 34 are positioned and installed by buckling the two-petal model frame 30 together. At the same time, a limiting ring 32 is set at the bottom of the model frame 30, and the limiting ring 32 is plugged into the rotating disk 4. An installation groove 350 is set between the upper mold frame 31, the lower mold frame 34 and the model frame 30 to install the spiral tube 35. After the casting is completed, cooling water is injected into the spiral tube 35 to accelerate the cooling of the casting. During cooling, cooling water is injected into the bottom of the spiral tube 35 through the vertical cooling pipe 36, and the cooling water flows out from the return pipe 37 at the upper end of the spiral tube 35. After the casting is completed, the casting mechanism 3 needs to be separated from the liquid feeding pipe 24 to carry out the casting operation of the next group of casting mechanisms 3. The motor 2 54 is fixedly installed by the mounting plate 1 51 and the mounting plate 2 53. When the motor 2 54 drives the worm 55 to rotate, the worm wheel 59 evenly arranged in the axial direction will rotate. When the worm wheel 59 rotates, it meshes with the vertical rack 510 inside the mounting cylinder 50, thereby driving the mounting cylinder 50 and the rotating disk 4 as a whole to perform lifting and lowering movements. After the casting mechanism 3 completes the casting of the molten metal, in order to facilitate the rapid casting operation of the next casting mechanism 3, an annular groove 1 62 is set at the plug-in part of the model frame 30, and cooling water is injected into the guide groove 1 61 in combination with the water tank 2 66 and the water outlet ball head 68. The cooling water enters the annular groove 1 62, the vertical groove 63, the annular groove 2 64, and the guide groove 2 65 along the guide groove 1 61, thereby quickly cooling the plug-in part of the model frame 30, so that the molten metal in the corresponding part of the lower mold frame 34 is quickly cooled and solidified, and then the lifting mechanism 5 can be combined to drive the rotating disk 4 to rise, so that the casting mechanism 3 is separated from the liquid delivery pipe 24, and the casting operation of the next group of casting mechanisms 3 is carried out. The guide groove 2 65 is connected to the receiving pipe 70 and the annular pipe 71. After the cooling water enters the annular pipe 71, it is guided into the water collecting groove 73 by the drainage pipe 72 to prevent the cooling water from dispersing and flowing.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. Any reference numeral in a claim shall not be regarded as limiting the claim involved.

[0057] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A nickel-aluminum bronze impeller sand casting bottom pouring process, characterized in that: The following steps are involved: S1. Alloy smelting: weigh 87-90 parts of Cu, 8-10 parts of Al, 3-5 parts of Fe, 3-5 parts of Ni, and 1-2 parts of Mn by weight, and put them into a smelting equipment for melting; S2. Casting system design: Use computer simulation software to design the casting system and optimize the position and size of the gate, riser and ingates; S3, mold preparation, making mold, sand mold shaping and box assembly; S4, casting, sending the molten metal into the ladle and slowly pouring it from the gate at the bottom of the mold; S5, solidification cooling, control the casting to gradually cool and solidify from the bottom to the top; S6, post-processing, demoulding and cleaning the casting in the mold, and removing the gate and riser; The equipment used in the above process comprises a medium frequency induction furnace, a casting cooling device, a demoulding cleaning device and a cutting device. The casting cooling device comprises a base (1), a mounting frame (2) is arranged on the base (1), a molten metal casting mechanism is arranged on the mounting frame (2), a rotating disk (4) is rotatably mounted on the base (1), a lifting mechanism (5) is arranged at the center of the rotating disk (4), the lifting mechanism (5) drives the rotating disk (4) to move up and down, a plurality of groups of casting mechanisms (3) are evenly arranged on the edge of the rotating disk (4), the molten metal casting mechanism is alternately connected with the plurality of groups of casting mechanisms (3) for casting, a cooling and cutting mechanism (6) is arranged at the mounting position of the casting mechanism (3) and the rotating disk (4), and a cooling mechanism (7) is arranged inside the casting mechanism (3).

2. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 1, characterized in that: The sand mold preparation material is silica sand or chromite sand.

3. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 1, characterized in that: The surface of the casting after demoulding is heat treated.

4. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 3, characterized in that: Ultrasonic or X-ray non-destructive testing is performed on heat-treated castings.

5. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 1, characterized in that: The molten metal casting mechanism comprises a pressurizer (21) arranged on a mounting frame (2), one end of the pressurizer (21) is connected to an inert gas tank, the other end of the pressurizer (21) is connected to a heating cylinder (20), the heating cylinder (20) is arranged in a closed manner, a crucible (22) is placed in the heating cylinder (20), an electric heating wire (23) is arranged on the outside of the crucible (22), a liquid feeding pipe (24) is fixedly installed on the side wall of the heating cylinder (20), one end of the liquid feeding pipe (24) passes through the heating cylinder (20) and the crucible (22) and extends to the bottom of the crucible (22), and the other end of the liquid feeding pipe (24) is butted against the bottom of the casting mechanism (3).

6. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 1, characterized in that: The casting mechanism (3) comprises a model frame (30) plugged into the edge of the rotating disk (4); the model frame (30) is arranged in a two-petal style; a limiting ring (32) is arranged at the bottom of the model frame (30); the model frame (30) is limitedly plugged into the rotating disk (4) through the limiting ring (32); a butt joint pipe (33) is arranged at the bottom of the model frame (30); the butt joint pipe (33) is butt jointed with the liquid delivery pipe (24); an upper mold frame (31) and a lower mold frame (34) are placed in the model frame (30); the upper mold frame (31) and the lower mold frame (34) are placed in the model frame (30); The sand mold between the mold frame (31) and the lower mold frame (34) forms a casting cavity. An installation groove (350) is provided between the upper mold frame (31), the lower mold frame (34) and the model frame (30). A spiral tube (35) is installed in the installation groove (350). The bottom of the spiral tube (35) passes through the model frame (30) and is connected to a vertical cooling tube (36). The upper end of the spiral tube (35) passes through the model frame (30) and is connected to a return water pipe (37). The vertical cooling tube (36) is connected to a cooling mechanism (7).

7. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 6, characterized in that: The cooling mechanism (7) comprises a fixedly mounted mounting frame (74), on which a water tank (75) is arranged, and the water tank (75) is connected to a filling pipe (76), and the filling pipe (76) is aligned with the top of the vertical cooling pipe (36).

8. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 7, characterized in that: The base (1) is provided with a central column (40), the lifting mechanism (5) is connected to the top of the central column (40), the rotating disk (4) is connected to the lifting mechanism (5), the lifting mechanism (5) comprises a first mounting disk (51) provided on the central column (40), a plurality of groups of connecting columns (52) are evenly arranged on the first mounting disk (51), a second mounting disk (53) is provided on the top of the connecting columns (52), a second motor (54) is fixedly provided on the second mounting disk (53), the second motor (54) is connected to an output shaft, the output shaft is connected to a worm (55), and a rotating mounting portion (56) is provided on the output shaft. The rotatable mounting portion (56) is provided with a mounting ring (57) for limited rotation, and a connecting frame (58) is evenly arranged around the circumference of the mounting ring (57). A worm wheel (59) is rotatably mounted on the connecting frame (58), and the worm wheel (59) and the worm (55) are meshed with each other. A mounting cylinder (50) is provided at the upper end of the rotating disk (4), and the mounting cylinder (50) is sleeved on the outer side of the worm wheel (59). A vertical rack (510) is provided on the inner side of the mounting cylinder (50), and the vertical rack (510) and the worm wheel (59) are meshed with each other. The mounting frame (74) is fixedly connected to the edge of the second mounting disk (53).

9. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 8, characterized in that: The cooling cut-off mechanism (6) comprises a second water tank (66), the second water tank (66) being fixedly mounted on the edge of the second mounting plate (53), the second water tank (66) being connected to a telescopic tube (67), the telescopic tube (67) being connected to a water outlet ball head (68), the rotating plate (4) being evenly provided with receiving grooves (60) corresponding to the casting mechanism (3), the water outlet ball head (68) and the receiving groove (60) being matched with each other, a first guide groove (61) being provided between the receiving groove (60) and the plugging portion of the model frame (30), an annular groove (62) being provided on the outer ring of the plugging portion of the model frame (30), a plurality of groups of vertical grooves (63) being evenly provided on the inner ring of the annular groove (62), an annular groove (64) being provided at the bottom of the vertical groove (63), the annular groove (64) being connected to a second guide groove (65), the second guide groove (65) being provided on the inner side of the rotating plate (4) and connected to the bottom of the rotating plate (4).

10. A nickel aluminum bronze impeller sand casting bottom pouring process according to claim 9, characterized in that: One end of the second guide groove (65) located at the bottom of the rotating disk (4) is connected to a receiving tube (70), the receiving tube (70) is connected to an annular tube (71), a drainage pipe (72) is provided at the bottom of the annular tube (71), a water collecting groove (73) is provided on the base (1), and the drainage pipe (72) is directly opposite to the water collecting groove (73).

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