477 results about "Investment casting" patented technology

The invention provides an anti-gravity investment casting device suitable for titanium alloy and a casting method of the anti-gravity investment casting device, belongs to the field of titanium alloy casting, and solves the problems that an existing anti-gravity forming device has a sealing problem and a riser tube cannot be centered with a pouring gate inlet of a mold shell. Wherein the lifting structure can drive the mold assembly to move in the vertical direction, a mold shell in the mold assembly is located in the sand box, the sand box abuts against the top face of the flange sleeve, the flange sleeve is arranged on the mold support in a sliding and penetrating mode, and the upper pressing plate abuts against the upper portion of the sand box and is connected with the mold support. The water-cooled copper crucible is located below the riser tube, a flange structure is arranged at the upper end of the riser tube, the positioning and centering structure is used for enabling a pouring gate inlet of the mold shell and the riser tube to be coaxially arranged, the sealing structure comprises a first sealing ring and a second sealing ring, the first sealing ring is located between the flange sleeve and the flange structure, and the second sealing ring is located between the flange sleeve and the flange structure. The second sealing ring is located between the flange sleeve and the middle partition plate. According to the device, the pouring gate inlet of the mold shell can be centered with the riser tube, and the lower working tank is completely sealed.

The invention relates to the technical field of investment casting, and particularly provides an investment casting automatic wax pattern welding equipment control method which comprises the following steps: extracting a peak value and duration from heating curve data, and judging a uniformity numerical value of interface temperature distribution through a numerical simulation method; according to the fusion depth change trend and the interface temperature distribution data, the quantized value of the quality index is calculated, and an evaluation result of the welding effect is obtained; if the quality index quantized value is lower than a preset threshold value, historical test data are extracted from a data analysis module, and the adjustment range of the process variable is determined; according to the process variable adjustment range, optimizing the parameter combination of the heating curve and the pressure curve, and generating new control strategy data through an iterative algorithm; new control strategy data is adopted to drive equipment to operate, and dynamic feedback values of the interface temperature and the fusion depth are obtained through a real-time monitoring system; and extracting abnormal fluctuation data from the dynamic feedback value, and judging the influence degree of the solidification rate change on the quality index in combination with a data analysis result.

The invention relates to the field of precision casting, and discloses a precision casting process for a stainless steel impeller for nuclear power, which comprises the following steps of: S1, pressing a wax mold by using an investment casting process, and connecting the wax mold into a tree shape by using a wax rod; s2, the surface of the wax mold is coated with a refractory material, dewaxing is conducted through dewaxing equipment after drying, a hollow shell is obtained, and then high-temperature roasting is conducted; s3, selecting duplex stainless steel to be smelted in an electric furnace, heating molten steel to a preset pouring temperature, and pouring the molten steel into the shell from the bottom or the side; s4, the shell is removed after being naturally cooled, and solution treatment is conducted on the impeller; s5, carrying out sand blasting, shot blasting and sand cleaning, and carrying out nondestructive inspection; wherein dewaxing equipment used in the step S2 comprises a tank body, a rotatable tray is arranged in the tank body, and a plurality of adjustable fixing clamps are arranged on the tray to meet the fixing requirements of different shells; the top of the tank body is provided with a feed port, a discharge port and an automatic sealing door, and the bottom is connected with a wax liquid collecting tank and is internally provided with a liquid level sensor; the inner wall of the tank body is provided with a heating cavity for containing heating elements, and the outer wall is wrapped with heat insulation materials.

The invention relates to the technical field of lost foam casting, in particular to a lost foam composite coating, the lost foam composite coating takes a refractory material of an investment casting regenerated shell membrane as a refractory aggregate, the refractory aggregate comprises mullite and a mixture containing an inorganic preservative A and a sintering stripping material B, and one or more of quartz powder and graphite are selected. In the invention, an efficient anti-corrosion additive with sintering stripping is researched and developed as a refractory material auxiliary additive, and meanwhile, low-price refractory materials such as regenerated mullite and recycled quartz powder are utilized to form the lost foam coating aggregate, so that the selection of traditional refractory aggregate is broken through, and the reutilization of waste resources is realized; the environment pollution is reduced while the raw material cost is reduced, meanwhile, the aggregate performance is optimized by adding the raw materials such as calcium oxide and iron oxide red, and the comprehensive performance such as air permeability, suspension stability, high-temperature strength and toughness of the coating is remarkably improved through reasonable matching of the composite binder.

The invention relates to a directional optimization method and system for investment casting parameters, and relates to the field of casting optimization. A quality monitoring database, mapped with a current parameter set, of an investment casting workpiece is established, a directional optimization target is configured, and a target classification identifier in the directional optimization target is determined; after key optimization parameters are selected through the main optimization target and the auxiliary optimization target, directional optimization target influence analysis of the key optimization parameters is executed, parameter directional optimization is executed after parameter optimization constraints are established according to the directional target optimization influence analysis result, and investment casting parameter directional optimization is completed through the parameter directional optimization result. The technical problems that investment casting parameter optimization is lack of systematicness and comprehensiveness, global optimization is difficult to achieve to improve the casting quality and production efficiency, the production cost is reduced, and the requirement of the market for high-quality castings is met are solved.

The invention provides a preparation method of a sand mold forming mold shell for titanium alloy precision investment casting, which comprises the following steps: S1, carrying out sand mold 3D printing on a three-dimensional sand mold to obtain a sand mold model; s2, a 3D printing spray gun is adopted for spraying the sand mold, the total spraying thickness is controlled to be 0.5-1 mm, low-temperature wax is adopted as a spraying raw material, and the model is K512; s3, a mold shell is prepared; s4, roasting and sand removal; the step S2 specifically comprises the following steps that S21, low-temperature wax is placed in a spray gun to be preheated, and the preheating temperature ranges from 50 DEG C to 60 DEG C; and S22, the temperature of the spray gun is increased to 60-120 DEG C, and a wax mold is sprayed on the sand mold. According to the preparation method, the 3D printing sand mold can replace a wax mold, and the problems of shrinkage deformation, shrinkage depression and the like of the wax mold are avoided; the spraying gun is used for spraying the 0.5-1 mm wax mould on the sand mould, the thickness is accurate and controllable, the sand mould model obtained by spraying the wax mould is smooth in surface and free of wax marks, the surface quality and the size precision of the titanium alloy casting can be effectively improved, manual finishing is not needed, and the manufacturing cost is low.

The invention relates to the technical field of titanium alloy investment precision casting, and particularly provides a titanium alloy multistage deep blind hole investment casting method which comprises the following steps: designing an exhaust hole and a slag removal hole; establishing a model; assembling and welding; soaking the surface layer in a vacuum negative pressure environment, continuously vacuumizing, deflating after soaking, taking out the module, and rotating to uniformly control the slurry; preparing a surface layer; performing segmented grouting on the deep blind hole; making a shell from a back layer; roasting and molding; washing and drying; pouring is conducted; shell cleaning and sand blasting; sealing and welding the process holes; and performing stress relief annealing. And a dynamic vacuumizing means is adopted, and a vacuumizing device is always kept in an open state, so that the compactness of a surface layer is improved, and burrs of a casting are reduced. Through vacuum dynamic slurry immersion, segmented grouting and collaborative design of the exhaust hole and the slag removal hole, investment precision casting forming of the high-precision oil pump shell can be supported, the shell manufacturing efficiency of the multi-stage deep blind hole is improved, and the filling defect rate is reduced.

The invention discloses a defect prediction method and system for an aircraft engine tail jet adjusting sheet investment casting, and belongs to the technical field related to casting and machine learning, and the method comprises the steps: carrying out the numerical simulation of an adjusting sheet casting and a pouring system through finite element simulation software, and obtaining the position and size distribution result of a casting defect, the result is converted into three-dimensional point cloud data; dividing the three-dimensional point cloud data into a training set and a verification set, and training a PointNet-based defect prediction model by using the training set; the prediction accuracy and generalization ability of the defect prediction model are evaluated through the verification set, and hyper-parameters are adjusted according to a verification result; and converting a to-be-predicted adjusting sheet casting pouring system three-dimensional model into three-dimensional point cloud data, inputting the trained defect prediction model, and outputting a casting defect position and a prediction result. According to the method, the defects that an existing finite element simulation method is long in time consumption and wastes computing resources are overcome.

The invention relates to the technical field of investment mold shell casting, in particular to an investment mold shell casting system which comprises a rack, a slurry barrel, a roasting furnace, a cooling barrel and a slag collecting barrel are sequentially installed on the rack in the clockwise direction, and multiple sets of regularly-distributed elastic striking rods are installed on the inner wall of the slag collecting barrel. A loading and unloading station is arranged at the position, corresponding to the position between the slurry barrel and the slag collecting barrel, of the machine frame, a casting frame is installed on the machine frame in a liftable mode, a transmission unit is arranged on the casting frame, and the transmission unit is in transmission connection with a rotating station frame capable of periodically rotating by 72 degrees and a rotatable transmission gear ring. The casting equipment has the beneficial effects that casting links such as ceramic slurry coating, roasting, cooling and slag collecting are integrated into the same equipment, and the orderly circulation of a parison among the links is realized through the slurry barrel, the roasting furnace, the cooling barrel and the slag collecting barrel which are sequentially arranged on the rack in the clockwise direction and the rotary station frame capable of periodically rotating.

A method of making an object through investment casting includes additively manufacturing a mold for the object with a printing head on a carriage supported by a frame with the mold being additively manufactured from multiple layers on a build platform supported by the frame. An interior surface of the mold is machined with a machining device on the carriage after a predetermined number of layers have been added to the mold through additive manufacturing. The object is investment cast by directing a casting material into the mold while the mold is supported by the build platform.

The invention relates to the technical field of investment casting, in particular to an anti-gravity pouring tool and method for aluminum alloy investment precision casting, and the tool comprises a bottom plate and an annular sliding rail; the annular sliding rail is mounted on the top surface of the bottom plate; a pouring hole is formed in the center of the bottom plate; a plurality of sliding blocks are installed on the annular sliding rail in a sliding mode, and each sliding block is provided with a locking structure. A stand column is vertically installed on the top of each sliding block. A transverse pressing rod is installed on each stand column, and a pressing screw is arranged at the cantilever end of each transverse pressing rod in a screwed mode. And the lower end of the pressing screw rod is used for pressing a shell placed on the bottom plate. According to the tool, rapid fixing and stable pouring of the shell are achieved, and the production efficiency is remarkably improved. Compared with a traditional sand filling pouring process, a sand box does not need to be adopted for carrying out sand filling operation, pouring can be carried out after the preheated shell is clamped and fixed through the anti-gravity pouring tool, and the pouring efficiency is greatly improved.

A complete investment casting experiment is carried out around an autonomously designed turbine blade mold, S1, S2 and S3 section sizes of a casting in different stages are collected, and a time sequence data set is established, including mold, wax pattern, directional solidification, mold shell removal, pouring system removal and ceramic core constraint removal. Analysis shows that the average deviation of the casting size evolves continuously in different stages (from 0.2134 mm to 0.1857 mm), deviation accumulation is achieved, and the influence degrees of all the stages are different. In order to effectively capture the changes of the casting, an LSTM neural network is adopted to mine size deep features and establish a time-varying model. The result shows that the LSTM considers the deformation history by virtue of the unique door structure, the prediction value of the average deviation of the casting in a single-step prediction task is 0.1832 mm, and the test average absolute percentage error (MAPE) is 1.35%; the MAPE of the multi-step prediction is 2.99%, and the MAPE of the final step is 6.63%. The research provides a new thought for intelligent development of the field of investment casting.

The invention relates to the technical field of precision investment casting, in particular to an optical lens motor base precision forming die which comprises a fixing plate, a forming mechanism is arranged at the top of the fixing plate, and an upper die plate is arranged at the top of the forming mechanism; the forming mechanism comprises a butt joint unit arranged in the center of the top of the fixing plate, the butt joint unit comprises a main body fixedly connected with the fixing plate, a first ejector block is slidably connected to the position, close to the bottom, in the main body, and lifting blocks are arranged at the positions, located on the periphery of the first ejector block, in the main body; a butt joint rod is slidably connected to the center position in the first ejector block, and a pressing block is slidably connected to the position, below the butt joint rod, in the main body. Through linkage of the module assembly and the butt joint unit, the problems of wax mold demolding deformation cracking and parting surface steps are solved, and the integrity of the wax mold is guaranteed; by means of linkage of the cutter and the exhaust groove, residual wax is automatically cleaned, manual operation is not needed, shrinkage porosity is avoided, and the structural stability of the base is guaranteed.

The invention relates to the technical field of investment casting, in particular to a preparation method of a high-dimensional-precision ceramic core and a casting forming method. The preparation method of the high-dimensional-precision ceramic core comprises the following steps: (a) designing a ceramic core structure and a wax shell structure for preparing the ceramic core structure according to the structure of a casting; (b) preparing a wax shell structure by adopting photosensitive resin in a 3D printing manner; (c) pouring slurry into the wax shell structure, and roasting to obtain a ceramic core; the slurry comprises silica sol, polyacrylamide and zircon powder, the mass ratio of the silica sol to the polyacrylamide is 100: (0.02-0.06), and the mass ratio of the zircon powder to the silica sol is (2.5-3.5): 1. The photosensitive resin is used for manufacturing the wax shell, so that the surface quality and the size precision of the manufactured ceramic core can be improved; moreover, a certain amount of polyacrylamide is added into the slurry for preparing the ceramic core, so that the production cycle of the ceramic core is remarkably shortened, and meanwhile, the raw material cost is low.

The utility model belongs to the technical field of investment casting, and discloses an anti-bubble assembly and a gypsum mold investment casting continuous pouring device, the anti-bubble assembly comprises a working box and a supporting base, the interior of the working box is fixedly connected with a servo motor, the tail end of an output shaft of the servo motor is fixedly connected with a main shaft, and the main shaft is fixedly connected with an anti-bubble assembly. A first bevel gear is fixedly connected to one end of the main shaft, a second bevel gear is connected to the outer side of the first bevel gear in a meshed mode, a connecting shaft is fixedly connected to the interior of the second bevel gear, a half-moon plate is fixedly connected to the top end of the connecting shaft, and a shifting rod is fixedly connected to the top end of the half-moon plate; a limiting clamping plate is arranged on the outer side of the half-moon plate in an attached mode, and a fixing table is fixedly connected to the top end of the limiting clamping plate. By means of the technical scheme, the problems that in the prior art, continuous pouring cannot be conducted in the casting process, the pouring work efficiency is reduced, large-scale pouring is not facilitated, the production efficiency is low, and benefits are low are solved.

The invention relates to the technical field of high-temperature alloy investment casting, in particular to a method for reducing mixed crystals and recrystallization at the abrupt change position of the section of nickel-based single-crystal high-temperature alloy, which comprises the following steps: (1) after wax mold pressing is completed and the wax mold is completely cooled, coating a low-melting-point wax material at the variable-section transfer R angle to expand the R angle and reduce stress concentration; (2) in the shell preparation process, a proper amount of furan resin is added into back layer slurry, meanwhile, a proper amount of wood dust is added into a back layer sanding material, and the deformability of the shell is improved; and (3) in the casting process of the casting, the drawing rate near the variable cross section is reduced to 1.5 mm / min-2 mm / min. According to the preparation method of the variable-cross-section nickel-based single-crystal high-temperature alloy casting, the problems of recrystallization and mixed crystals of the variable-cross-section casting with a complex structure are solved through the synergistic effect of adjusting the size of the angle R, the shell manufacturing process, the drawing rate near the variable cross section and the like, and the provided preparation method of the variable-cross-section nickel-based single-crystal high-temperature alloy casting is easy to operate and implement and reduces the production cost.

The invention provides a preparation method of a zirconium acetate surface layer shell for titanium alloy precision investment casting, which comprises the following steps: S1, taking a zirconium acetate binder and an anti-redissolution inhibitor, adding an adhesion promoter and deionized water under a stirring condition, and uniformly stirring to obtain a surface layer binder; s2, mixing a surface layer binder with the surface layer refractory powder, adding a wetting agent, and uniformly dispersing the materials to obtain a surface layer coating; s3, performing vacuum negative pressure defoaming on the surface layer coating; s4, in a vacuum negative pressure state, after the wax mold is subjected to uniform slurry soaking in the surface layer coating and pressure maintaining is conducted for 60-300 s, sand spraying and drying are conducted on the wax mold subjected to slurry soaking, and a surface layer shell is obtained; s5, a dewaxing hole of the surface layer shell is opened, and staged hot steam dewaxing is carried out; s6, the dewaxed surface layer shell is roasted, and a shell is obtained; according to the method, redissolution of the zirconium gel surface layer can be effectively inhibited, the compactness of the surface layer can be improved, and the conditions of redissolution, peeling, falling and the like of a zirconium gel surface layer shell process in titanium alloy precision investment casting can be obviously improved.

The invention relates to the technical field of investment casting, in particular to an investment casting shell making method of an air inlet casing casting and a shell. The method comprises early-stage preparation (high-precision wax mold manufacturing and module assembling), a shell manufacturing process (shell manufacturing of a surface layer, a transition layer and a back layer) and subsequent procedures (dewaxing, roasting, pouring, cleaning and detecting). The surface layer and the transition layer are dried by silica sol-based paint (zircon powder / mullite powder) in cooperation with strong wind power, so that the surface quality and the initial strength are ensured; the back layer is hardened by adopting a water glass-based coating (coal gangue powder) matched with ammonium chloride, so that the supporting strength and air permeability of the main body are provided. By optimizing a composite shell-making material system and process parameters, the problem that in the prior art, the strength, the air permeability, the quality and the efficiency of a shell are difficult to consider at the same time is solved, and the method is particularly suitable for production of complex thin-wall castings such as aero-engine air inlet casings with extremely high requirements for the surface quality, the size precision and the internal structure; the defects of air holes, slag inclusion and the like can be effectively reduced.

The invention provides a pouring production line and a pouring method for investment casting, and particularly relates to the field of investment casting. The pouring production line comprises a smelting furnace, a mold shell conveying line, a pouring truck, a roasting furnace, a cover box lifting conveyor, a solidification cooling mechanism, a feeding transfer mechanism and a discharging transfer mechanism. The mold shell conveying line is arranged in front of the smelting furnace and comprises a first guide rail and a second guide rail which are oppositely arranged, and a third guide rail and a fourth guide rail which are located at the two ends of the first guide rail and the two ends of the second guide rail, and the roasting furnace, the cover box lifting conveyor and the solidification cooling mechanism are sequentially arranged along the second guide rail. The feeding transfer mechanism is arranged on the third guide rail and can transfer the tray loaded with the mold shell to a pouring truck for pouring; and the discharging and transferring mechanism is arranged on the fourth guide rail, and after pouring is completed, the tray loaded with the casting mold shell is transferred to the solidifying and cooling mechanism to be solidified and cooled. The production line can improve the quality of castings and improve the production efficiency.

The invention discloses a preparation method of a ceramic core plasticizer for high-temperature alloy investment casting, and relates to the technical field of plasticizers, and the preparation method comprises the following preparation steps: step 1, adding microcrystalline wax into modified chlorinated paraffin, heating, stirring and melting, adding a heat stabilizer, mixing, continuously stirring, heating for reaction, adding polyethylene wax, and continuously stirring; 2, after cooling, adding stearic acid, and continuously stirring; and 3, granulating and packaging to obtain the special plasticizer for the ceramic core. According to the preparation method of the ceramic core plasticizer for high-temperature alloy investment casting, polar groups such as hydroxyl groups and ester groups are introduced to a chlorinated paraffin molecular chain, strong interaction is formed between the polar groups and hydroxyl groups on the surface of ceramic powder, and a uniform wax coating layer is formed on the surface of powder particles.

The invention discloses an Nb-Si-Ti-Cr-Al-Hf alloy turbine ultrahigh-temperature investment casting method. The method comprises the following steps: preparing an alloy turbine ultrahigh-temperature investment casting shell; performing ultrahigh-temperature investment casting on the alloy turbine; and post-processing the alloy turbine casting. The microstructure and the mechanical property of the Nb-Si-based alloy are improved through alloying, the solidification path of the alloy is changed, the eutectoid reaction of metastable-phase Nb3Si is promoted, and the comprehensive performance is improved. Through the rare earth yttrium oxide shell, the problem that the alloy reacts with the shell is solved; high surface quality, strength and thermal shock resistance of the alloy turbine are ensured by regulating and controlling the powder-liquid mass ratio of the slurry and the number of shell layers; and a casting of which the tail end of the blade can be completely filled and has no metallurgical defect is cast through an induction suspension smelting technology, so that the alloy turbine cast by the ultra-high-temperature investment casting can meet the actual application requirement.

The invention relates to the technical field of investment casting processes, in particular to a forming process of a microminiature titanium alloy wireless earphone casting in the 3C field. S2, the wax mold is installed and welded; s3, coating dip-coating; s4, assembling and welding the wax mold and the pouring gate; s5, making a shell; s6, forming and pouring are conducted; and S7, shell cleaning is conducted on the poured mold shell. By using the combination of the straight pouring gate, the plurality of transverse pouring gates and the inner pouring gate, the inner pouring gate adopts a combined composite assembling mode of the combination of the inner straight pouring gate and the plurality of inner transverse pouring gates, and molten metal flows in a mold cavity under the centrifugal effect and is smoothly filled. Through production verification, the forming rate of the micro-miniature complex thin-wall titanium alloy part cast through the method reaches 100% at most, and the phenomenon of insufficient casting does not occur.

In order to improve the metallurgical quality of a thin-wall casting in the investment casting process, the invention provides a novel control method based on machine learning and a sequential solidification principle. The method comprises the steps that firstly, geometric structure parameters related to the solidification process are calculated on discretization representation of a casting model, and the geometric structure parameters comprise the distance from a local position to a casting head, the geometric modulus and the mold shell thickness; secondly, in combination with a numerical simulation result, a random forest algorithm is used for establishing a mapping model of geometric structure parameters and solidification time of the casting, and R2 on a verification set is 0.9974; based on the model, the gradient of a solidification curve on a geodesic path is quantitatively adjusted in combination with measures of local formwork thickness reduction and heat preservation cotton coating, and sequential solidification is achieved. And after optimization, the total shrinkage porosity volume of the casting is reduced to 24.78 mm < 3 > from 71.69 mm < 3 >, and is reduced by 65%. The effectiveness of the method is further verified through a pouring experiment, an efficient and quantitative solution is provided for shrinkage porosity control of the thin-wall complex casting, and a new thought is provided for intelligent control over investment casting defects.

The present application relates to wax mold technology field, disclose a kind of large thin-walled wax mold and for wet wax precision casting production process, including fixing frame, the fixing frame is provided with electric push rod, movable mould and fixed mould, the movable mould, fixed mould is provided with heat dissipation mechanism, the movable mould is provided with stripping mechanism, the fixed mould is provided with top pressure mechanism and wax injection port, the movable mould is also provided with rotating mechanism, the rotating mechanism includes motor and locking piece.The present application can demould the workpiece, while avoiding the workpiece from being stuck in the fixed mould, thereby greatly improving the practical convenience, and after demoulding the workpiece, water-based release agent can be sprayed in the fixed mould and movable mould, thereby avoiding the need for manual spraying of water-based release agent, and the forming effect and forming quality of the workpiece can also be improved, finally the locking piece can be automatically driven to contact and lock the fixed mould, thereby greatly improving the practicality and convenience of use.

The invention discloses a multi-stage composite sand cleaning method and system for investment casting of a narrow inner cavity casting, and relates to the technical field of investment casting, the method comprises the following steps: S1, primary shot blasting cleaning is carried out to remove floating sand on the outer surface of the casting and a shallow inner cavity, and a deep sand inlet is exposed; s2, inner cavity impact sand loosening is conducted, specifically, a sand body blocked in the deep portion of the inner cavity of the casting cracks and loosens through pneumatic impact; s3, ultrasonic vibration sand removal is conducted, specifically, the casting is installed on a special tool, loose sand grains are stripped from the inner cavity wall through ultrasonic vibration output by an ultrasonic generation unit, and a tuning control module is arranged to conduct real-time scanning on the casting and adjust the frequency of the ultrasonic vibration so as to be matched with the local resonance frequency of the inner cavity of the casting; s4, secondary shot blasting finishing is conducted, falling residual sand in the casting is removed, and surface finishing is achieved; and efficient, thorough and damage-free sand removal of sand grains in narrow, bent and deep inner cavities of the casting is realized through the multi-stage sand removal step.

The invention relates to a jeweler's rubber mold pressing device that ensures the alignment and placement of a two-part (upper and lower) rubber mold used in the injection of wax into rubber molds for jewelry investment casting technology. This is achieved by pressing the mold and aligning it with the injection nozzle of the injection machine in both vertical and horizontal directions, and then pushing it onto the nozzle.

The utility model discloses a sand spraying machine for investment casting, which is characterized in that the upper end of a base is provided with a sand spraying barrel body, the side wall of the upper end of the sand spraying barrel body is provided with a fixing bracket for fixing a wax mold, the upper end of the sand spraying barrel body is provided with a sand screening mechanism, the sand screening mechanism comprises an annular sand screening plate, and the sand screening plate is inclined downwards from the outer end to the inner end; the sand spraying barrel body comprises a coarse material collecting cavity formed in the middle and a fine material collecting cavity formed in the outer end, a bottom plate of the coarse material collecting cavity is higher than a bottom plate of the fine material collecting cavity, the sand spraying machine further comprises a sand pumping mechanism used for conveying sand in the fine material collecting cavity to the position above the outer end of the sand screening plate, and the inner end of the sand screening plate extends to the upper end of the coarse material collecting cavity. According to the sand spraying machine, the sand spraying barrel body is divided into the coarse material collecting cavity and the fine material collecting cavity, fine materials fall onto a wax mold from screen holes of the sand screening plate to be subjected to sand spraying operation, coarse sand directly falls into the coarse material collecting cavity through the sand screening plate to be recycled, efficient screening, conveying and recycling of the sand are achieved, and the utilization efficiency of the sand is improved.

The application relates to the technical field of investment casting and discloses an exhaust manifold investment casting equipment based on a hierarchical cooling shaping structure, which comprises a mold group, a main pipe core-pulling module and a branch pipe core-pulling module, the inside of the mold group is provided with a mold cavity, and the inside of the mold group is provided with a cooling pipeline; wherein the main pipe core-pulling module comprises a sliding block one, and the side close to the mold group of the sliding block one is fixedly installed with a core-pulling block. The exhaust manifold investment casting equipment based on the hierarchical cooling shaping structure can effectively solve the problem that, in the prior art, the conventional investment casting wax injection mold usually adopts an integral fixed core-pulling structure, and when the core-pulling is performed on the main pipe end of the exhaust manifold, due to the complex inner cavity curved surface at the intersection of the main pipe and the branch pipe of the exhaust manifold, the diameter of the arc connection at the intersection is greater than the diameter of the outer end of the main pipe, the contact area between the core body of the existing core-pulling structure and the inner wall of the wax mold is large, the friction force is strong, and the inner wall of the wax mold is prone to scratching, pilling and even tearing.

The utility model relates to the technical field of wax liquid processing, in particular to a stirring device for investment casting wax liquid, which comprises a tank body, the top of the tank body is connected with a cover in a pluggable manner, the outer part of the tank body is fixedly connected with a reinforcing ring, the bottom end of the tank body is fixedly connected with supporting legs, and an extension rod is fixedly connected between the supporting legs. The top end of the inner side of the tank body is fixedly connected with a bearing plate, the bottom of the bearing plate is fixedly connected with a funnel, the bottom of the funnel is fixedly connected with an extension cylinder, the funnel is communicated with the interior of the extension cylinder, the inner side wall of the funnel is provided with a filter screen, and the bottom of the extension cylinder is fixedly connected with a sleeve; compared with an existing stirring device for the investment casting wax liquid, the stirring device for the investment casting wax liquid has the advantages that through the design of the filter screen and the scraping rod, solid-liquid separation of the wax liquid can be rapidly completed, the inner wall of the tank body is cleaned, and the overall practicability is greatly improved.

The invention relates to the technical field of investment casting, in particular to a method for reducing microporosity of a secondary aluminum alloy and an investment casting method. The method for reducing microporosity of the secondary aluminum alloy comprises the following steps that secondary aluminum alloy molten metal is poured into a mold shell, cooling and solidification are conducted after pouring is completed, and a casting is obtained; pressurizing a pouring chamber where the mold shell is located at the beginning of pouring, and stopping pressurizing until the molten metal is cooled to 400 DEG C; during pressurization, pressure is applied, so that the initial pressure P0 of the pouring chamber is 1.2-4 times of the standard atmospheric pressure. According to the method, in the pouring process of the secondary aluminum alloy molten metal, certain pressure is applied, so that microporosity of the surface and the interior of the secondary aluminum alloy casting can be greatly reduced, and the yield of the casting is greatly improved.