Flaskless casting method for manufacturing thin-walled aluminum alloy castings

Abstract

The present invention relates to a boxless casting manufacturing method for a thin-walled rotating aluminum alloy casting, comprising the following steps: installing a tool for boxless casting on a workbench; taking out a product mold and a pouring and rigging system mold after the molding sand is solidified to form the product shape and the cavity sand mold of the pouring and rigging system; filling the molding sand into the product core box, pounding and splitting the core box to obtain a mud core; smelting the alloy liquid; treating the seams on the mud core and applying a coating; combining the sand mold and the mud core to confirm that the cavity gap between the inner wall of the sand mold and the outer wall of the mud core meets the requirements; performing boxless casting on the workbench, injecting the alloy liquid into the cavity, cleaning the sand after cooling, and obtaining a casting; removing the pouring and rigging system on the casting, and polishing the appearance of the casting; performing solid solution heat treatment on the casting; performing rotary extrusion shaping on the casting so that the casting reaches a casting state within the dimensional tolerance range; and placing the casting in an aging furnace for aging treatment. The present invention can greatly simplify the casting process and improve product quality.

Description

Technical Field

[0001] The invention relates to a precision casting method, in particular to a boxless casting manufacturing method for a thin-walled rotating body aluminum alloy casting, and belongs to the technical field of precision casting. Background Art

[0002] The sand mold is a casting cavity made of raw sand, binder and other auxiliary materials in the casting production process. The traditional process uses a sand box to complete the sand mold. The molding sand pounded tightly in the upper and lower sand boxes together with the upper and lower sand boxes are called the upper sand mold and the lower sand mold respectively. After the pattern is taken out of the sand mold, the cavity left is called the mold cavity.

[0003] The core is commonly known as the "mud core". It is used to form the internal structure of the casting during casting. It is usually made of core sand made of raw sand and a binder. It is made by hand or machine in a core box. The core box is usually made of wood or metal. The core is installed in the sand mold before casting. After the molten metal is poured in and condensed, it is removed when the sand is discharged, and a cavity can be formed in the casting.

[0004] The mud core of the rotating body casting is a cylinder. Due to the limited mold parting method, the cylindricity error of the mud core is large, and there is a lack of effective control means, which affects the roundness of the inner wall of the finished casting. The traditional mud core repair is repaired by size templates, files, and calipers. For the mud core of the rotating body with high precision requirements, the manual force and mold opening frequency cannot be controlled when the mud core is opened. In addition, the error of the mold itself and the compactness error of the mud core will lead to the error of the cylindricity of the mud core itself, which cannot meet the high-precision requirements. Generally, the mud core is painted by manual brushing, manual dipping and manual spraying. The thickness of the coating layer varies from 0.2-0.5mm, which will increase the size error of the mud core.

[0005] The molten metal is poured into the cavity, and the metal casting is formed after cooling. Before obtaining the metal casting, the sand mold must be cleaned. There are two types of traditional sand mold cleaning: manual sand cleaning and mechanical vibration sand cleaning. The former requires the use of a crane to lift the sand box to the designated sand drop point, and then several people use a hammer to break the sand mold, which is time-consuming and labor-intensive, and easily causes damage to thin-walled castings; depending on the size of the sand mold, it takes from dozens of minutes to several hours, with low efficiency and high labor costs. The latter directly transfers the sand box into the sand vibration machine, starts the machine, and performs sand cleaning through vibration combined with manual assistance. Although it is efficient, the investment cost is high, and it is necessary to purchase equipment and establish a sand drop production line, which has certain requirements for the use area of ​​the factory. There are some restrictions on the scale of casting of small batches and multiple varieties.

[0006] Heat treatment strengthening of cast aluminum alloys usually adopts solution treatment and aging treatment. Traditionally, the castings to be heat treated are stacked together in a frame, and the castings will be deformed due to the number of stacking and the uneven placement. In order to consider the economy of production electricity, each heat treatment furnace will be fully loaded; this will cause deformation of the castings, especially thin-walled rotating aluminum alloy castings with a thickness of less than 5mm, which have a greater risk of deformation and the direction of deformation cannot be predicted.

[0007] When deformation occurs, it can only be corrected through manual shaping and real-time measurement, because after solution treatment, the temperature of the casting surface reaches the boiling water temperature, and manual shaping and measurement will face the risk of burns, and the measuring tool will also have errors at higher temperatures, affecting the accuracy of shaping. In addition, if conditions permit, shaping by press requires shaping tools of different diameters, which increases the cost investment, and the tools and equipment need to be maintained regularly. Summary of the invention

[0008] The purpose of the present invention is to overcome the problems existing in the prior art and provide a boxless casting manufacturing method for thin-walled rotating aluminum alloy castings, which can greatly reduce the use of molds and the cost of tooling, simplify the manufacturing process, use simple tooling to improve the entire manufacturing process, and improve product quality.

[0009] In order to solve the above technical problems, a flaskless casting method for manufacturing thin-walled rotating aluminum alloy castings of the present invention comprises the following steps in sequence:

[0010] S1. Install the tooling for boxless pouring on the workbench;

[0011] S2. Sand mold modeling: Combine the product mold and the pouring system mold with the modeling sand, and take out the product mold and the pouring system mold after the modeling sand is solidified to form the product shape and the cavity sand mold of the pouring system;

[0012] S3, core making: fill the product core box with modeling sand, pound it, split the core box and get the mud core;

[0013] S4, alloy liquid smelting;

[0014] S5. Process the seams on the mud core and apply paint on the workbench;

[0015] S6. Combine the sand mold and the clay core to confirm that the cavity gap between the inner wall of the sand mold and the outer wall of the clay core meets the size requirements of the drawing;

[0016] S7, perform boxless pouring on the workbench, inject the alloy liquid into the mold cavity, and perform sand cleaning after cooling and molding to obtain a casting with a pouring and rigging system;

[0017] S8. Remove the pouring system on the casting and polish the appearance of the casting;

[0018] S9, performing solution heat treatment on the casting;

[0019] S10, performing rotational extrusion shaping on the casting so that the casting reaches a casting state within a dimensional tolerance range;

[0020] S11. Place the casting into an aging furnace for aging treatment.

[0021] As an improvement of the present invention, the boxless casting tooling described in S1 includes a horizontal base plate fixed on a workbench, a circular base plate countersunk hole is provided in the center of the horizontal base plate, a base plate center hole is provided in the center of the bottom countersunk hole, a platform rotating cover is supported on the bottom wall of the base plate countersunk hole through a plane bearing, and an adjusting motor for driving the platform rotating cover to rotate is installed at the bottom center of the workbench; slider grooves are provided on the horizontal base plate and symmetrically located around the platform rotating cover, sliders are respectively embedded in the slider grooves, and a rotatable slider adjustment screw is respectively connected to the outer side of each slider, and the threaded section of each slider adjustment screw is respectively screwed into the screw hole of the horizontal base plate; a slider countersunk groove is provided in the center of the top of each slider, and a slider locating pin is provided on the bottom wall of the slider countersunk groove.

[0022] As a further improvement of the present invention, in S4, after the alloy ingot and the master alloy are melted, the refining agent, the refiner and the covering agent are added to the molten liquid in proportion, and the mixture is stirred and degassed until the chemical composition is qualified.

[0023] As a further improvement of the present invention, S5 includes the following sub-steps:

[0024] S5.1. Fix the mud core on the platform rotating cover and keep it coaxial;

[0025] S5.2. An adjusting vertical rod is fixed on each slider, and an adjusting vertical rod embedding groove extending vertically is provided on the inner side of each adjusting vertical rod. The cross section of the adjusting vertical rod embedding groove is dovetail-shaped and opens toward the axial direction of the platform rotating cover;

[0026] S5.3. Insert scraper blades extending vertically into the grooves of the vertical adjustment rods respectively, and the dovetail tenon at the root of each scraper blade matches the groove of the vertical adjustment rod; rotate the slider to adjust the screw rod so that the active surface of each scraper blade fits on the circumference of the mud core respectively;

[0027] S5.4. Drive the rotating cover of the platform to rotate at a speed of 30-50rpm until no false sand falls off; then inject paint to the top of each scraper blade near the top of the dovetail through the air pipe. The paint first reaches the bottom of the paint cavity downward, then reaches the upper part of the paint cavity upward, flows out from the upper part of the scraper blade action surface and is smeared on the outer wall of the mud core.

[0028] As a further improvement of the present invention, in S5.2, the lower end of each adjusting vertical rod is respectively embedded in the corresponding slider groove, and the slider locating pins are respectively inserted into the locating holes at the bottom of the adjusting vertical rod; adjusting vertical rod bosses are respectively provided on both sides of the bottom of each adjusting vertical rod, and the adjusting vertical rod bosses are fixed to the top of the slider by adjusting vertical rod fixing screws.

[0029] As a further improvement of the present invention, S7 includes the following sub-steps:

[0030] S7.1. Screw a sleeve into the center hole of the platform rotating cover, wherein the lower part of the sleeve is a belt driving end, and the belt driving end is connected to the output end of the regulating motor through a belt;

[0031] S7.2, inserting a liquid riser into the inner cavity of the insert sleeve, two balls are arranged between the outer periphery of the liquid riser and the inner wall of the insert sleeve, and the top outlet of the liquid riser is connected to the gate at the lower end of the sand mold;

[0032] S7.3. Insert the sand mold support plates into the grooves of the adjusting vertical rods respectively. The roots of the sand mold support plates are respectively embedded in the grooves of the adjusting vertical rods through dovetail tenons. The inner side surfaces of the sand mold support plates are respectively tangent to the outer wall of the sand mold by rotating the slider to adjust the screw rod.

[0033] S7.4. Adjust the motor to drive the platform rotating cover to rotate at a speed of 30-50 rpm, and inject the alloy liquid into the cavity through the liquid riser. After the alloy liquid is cooled, a casting and a pouring system are formed;

[0034] S7.5. Remove each adjustment vertical rod, fix the adjustment frame on each slider, provide a continuous adjustment frame vertical slot along the height direction of the adjustment frame, install a plurality of positioning blocks along the height direction of the adjustment frame vertical slot, and provide positioning block tenons on both sides of each positioning block, and the positioning block tenons are respectively embedded in the horizontal embedding grooves on the side walls of the adjustment frame vertical slot;

[0035] S7.6. Insert a sleeve into the inner port of the center hole of each positioning block, and plug and fix the cutter into the inner port of the center hole of the sleeve;

[0036] S7.7. The motor is adjusted again to drive the platform rotating cover to rotate at a speed of 40-60rpm. At the same time, the slider is manually adjusted by shaking the screw rod to make the slider gradually move inward. After each cutter cuts the sand mold, the sand is manually cleaned and the casting with the pouring system is taken out.

[0037] As a further improvement of the present invention, in S7.5, the lower end of each adjustment frame is respectively embedded in the corresponding slider groove, and the slider locating pins are respectively inserted into the locating holes at the bottom of the adjustment frame; adjustment frame bosses are respectively provided on both sides of the bottom of each adjustment frame, and the adjustment frame bosses are fixed to the top of the slider by adjusting frame fixing screws.

[0038] As a further improvement of the present invention, S8 includes the following sub-steps:

[0039] S8.1. Remove the runner system connected to the casting by sawing.

[0040] S8.2, turning the outer diameter of the casting by lathe;

[0041] S8.3. Measure the dimensions of the castings according to the drawings and visually inspect the appearance for casting defects;

[0042] S8.4. Inspect castings for internal defects by X-ray and fluorescence.

[0043] S8.5. Weld repairs shall be performed on the parts with internal defects exceeding the standard detected by X-ray and fluorescence inspection;

[0044] S8.6. Lathe the welded parts of the casting.

[0045] As a further improvement of the present invention, S9 includes the following sub-steps:

[0046] S9.1. Place the casting steadily on the solid solution bottom plate, and the arc blocks on the upper surface of the solid solution bottom plate evenly abut against the outer side of the lower end of the casting;

[0047] S9.2. Insert the lower end of each limiting tube into the bottom plate plugging countersunk holes evenly distributed on the outer periphery of the solid solution bottom plate, each bottom plate plugging countersunk hole is provided with a radial limiting block, and the bottom of each limiting tube is provided with a radial embedding groove clamped on the corresponding radial limiting block;

[0048] S9.3. Place a circular gland on the casting, the upper end of each limiting tube passes through the guide hole of the circular gland, and the side wall of each limiting tube is tangent to the outer periphery of the casting;

[0049] S9.4. Screw an upper nut onto each of the two long fixed screws and rotate them to the top. Insert the two long fixed screws symmetrically into the gland screw mounting holes on the circular gland, and pass through the inner cavity of the casting and out of the base plate screw mounting holes.

[0050] S9.5. Screw the lower nut on the lower end of the fixed long screw and press it on the lower end surface of the solid solution bottom plate, and keep the lifting rings on the top of the two fixed long screws at the same height. Then screw the upper nut downward and press it on the upper end surface of the circular gland, so that the circular gland and the solid solution bottom plate are connected as a whole and the upper ends of each limit tube remain in a floating state;

[0051] S9.6. Pass the steel wire rope through the lifting ring, lift the solid solution tooling as a whole, and put it into the oven for heating and heat preservation;

[0052] S9.7. After the insulation is completed, lift the solution treatment tooling as a whole and put it into a 60-80℃ water pool for rapid cooling for 10 minutes before taking it out.

[0053] As a further improvement of the present invention, S10 includes the following sub-steps:

[0054] S10.1. Remove the sleeves and cutters from the positioning blocks on the adjustment frame;

[0055] S10.2. Insert the roller rod from the rear end into the center hole of the positioning block. The fork head at the front end of the roller rod extends from the front end of the center hole of the positioning block. Install the roller shaft and the roller between the forks of the roller rods.

[0056] S10.3. Insert the spring and the limit rod into the center hole of the positioning block from the rear end in sequence, with the front end of the spring resting on the roller rod boss and the rear end of the spring resting on the inner end surface of the limit rod;

[0057] S10.4. A digital display rod is fitted and fixed on the outside of each adjustment frame. A plurality of digital display rod mounting holes are respectively provided on the digital display rod in the height direction. A sensing screw seat is screwed into each digital display rod mounting hole. A sensing sheet is respectively installed on the side of each sensing screw seat facing the adjustment frame. Each sensing sheet is respectively against the outer end of the corresponding limit rod;

[0058] S10.5. Fix the pre-processed tray matching the casting coaxially above the platform rotating cover;

[0059] S10.6. The lower end of the casting is embedded in a tray. The outer edge of the tray is provided with an annular vertical edge standing upright upward. Multiple radial screws are evenly screwed along the circumference of the annular vertical edge to fix the bottom of the casting;

[0060] S10.7. Adjust the induction screw seat to make the distances between the four induction plates on the same circumference and the axis of the casting equal;

[0061] S10.8. The motor is adjusted to drive the casting to rotate. Four rollers at different heights rotate, extrude and shape the casting so that the roundness of the casting meets the tolerance requirements.

[0062] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. Using the same workbench for multiple processes greatly reduces the tooling production cost and production cycle; fewer molds are used, the process is simplified and easy to operate, and the finished product quality is high.

[0063] 2. The motor is adjusted to drive the platform rotating cover and the mud core to rotate slowly, and the scraper blade is used to scrape the outer periphery of the mud core. While scraping, paint is applied to the outer periphery of the mud core. The mud core is accurately positioned and the outer circumference is trimmed by four scraper blades to reduce its cylindricality error and improve the accuracy of the mud core. The paint is applied simultaneously while the mud core is being trimmed, eliminating the subsequent painting process.

[0064] 3. During pouring, the sand mold support plate supports the outer periphery of the sand mold to prevent the sand mold from tilting; after the casting is cooled and formed, the sand mold support plate can be replaced with a cutting tool to remove the sand mold, which is very quick and convenient, greatly improving production efficiency, and there is no need to purchase expensive equipment.

[0065] 4. During solution treatment, each stopper tube is inclined along the draft taper of the thin-walled aluminum alloy rotating body casting and is tangent to the outer wall of the thin-walled aluminum alloy rotating body casting. During the heating, insulation and cooling process, the tube restrains the outer circumference of the casting to keep it round and reduce deformation. The stopper tube is in line contact with the outer wall of the casting, which does not affect its uniform cooling.

[0066] 5. During shaping, the motor is adjusted to drive the platform rotating cover, tray and casting to rotate slowly. The tray is precisely processed and matched according to the size of the casting. The casting is still in a soft state after solution treatment and before aging. The four sets of rollers on the outside are used to accurately position the casting at each height and squeeze the outer circumference, so that the cylindricity error of each section of the casting meets the tolerance range, thereby improving the product accuracy and quality. Both tapered castings and cylindrical castings can be shaped. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The accompanying drawings are only provided for reference and explanation and are not intended to limit the present invention.

[0068] Figure 1 It is a three-dimensional diagram of the mud core during rotation and shaping in the present invention;

[0069] Figure 2 for Figure 1 Exploded diagram of

[0070] Figure 3 for Figure 1 The main cross-sectional view of

[0071] Figure 4 for Figure 3 A magnified view of the middle scraper blade;

[0072] Figure 5 A three-dimensional diagram of the present invention during pouring;

[0073] Figure 6 This is an exploded view of the present invention after the sand mold and the platform rotating cover are removed during pouring;

[0074] Figure 7 It is a cross-sectional view of the present invention during pouring;

[0075] Figure 8 An exploded view of the sand mold and the structure below it in the present invention;

[0076] Fig. 9 It is a three-dimensional diagram after the sand mold is hidden during sand cleaning of the present invention;

[0077] Fig.10 for Fig. 9 Exploded diagram of

[0078] Fig.11 It is a cross-sectional view after the sand mold is hidden during sand cleaning of the present invention;

[0079] Fig.12 It is a three-dimensional diagram of the heat treatment solution tooling in the present invention;

[0080] Fig.13 for Fig.12 Exploded diagram of

[0081] Fig.14 It is a stereoscopic diagram of the rotary extrusion shaping in the present invention;

[0082] Fig.15 for Fig.14 The main cross-sectional view of

[0083] Fig.16 for Fig.15 A partial enlarged view of the

[0084] Fig.17 This is the exploded view after omitting the tray and part of the digital display rod on the horizontal base plate.

[0085] In the figure: 1. workbench; 2. adjustment motor; 2a. belt; 3. horizontal bottom plate; 3a. bottom plate countersunk hole; 3b. bottom plate center hole; 3c. slider groove; 3d. bottom plate adjustment screw; 4. plane bearing; 5. platform rotating cover; 6. slider; 6a. slider groove; 6b. slider positioning pin; 6c. slider adjustment screw; 7. adjustment vertical rod; 7a. adjustment vertical rod groove; 7b. adjustment vertical rod boss; 7c. adjustment vertical rod fixing screw; 8. scraper blade; 8a. scraper blade dovetail; 8b. paint injection port; 8c. paint cavity; 8d. paint outflow port; 9. mud core; 10. sleeve; 10a. belt drive end; 11. liquid riser; 12. ball; 13. adjustment frame; 13a. adjustment frame vertical groove; 13b. horizontal groove; 13c. adjustment frame boss; 13d. adjustment frame fixed screw Set screw; 14. Sand mold backing plate; 14a. Backing plate dovetail; 15. Sand mold; 15a Gate; 16. Positioning block; 16a. Positioning block tenon; 17. Sleeve; 18. Cutter; 19. Casting; 20. Tray; 21. Radial screw; 22. Roller rod; 23. Roller; 24. Spring; 25. Limit rod; 26. Digital display rod; 27. Sensor sheet; 28. Sensor screw seat; 29. Solid solution base plate; 29a. Solid solution base plate center hole; 29b. Arc block; 29c. Base plate plug-in countersunk hole; 29d. Radial limit block; 29e. Base plate screw mounting hole; 30. Round gland; 30a. Guide hole; 30b. Gland screw mounting hole; 31. Limiting tube; 31a. Radial embedded groove; 32. Fixed long screw; 32a. Lifting ring; 33a. Upper nut; 33b. Lower nut. DETAILED DESCRIPTION

[0086] In the following description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific position. The installation of a new component in the slider herein indicates that the old component has been removed.

[0087] The flaskless casting method for manufacturing thin-walled aluminum alloy rotating body castings of the present invention comprises the following steps in sequence:

[0088] S1. Install the tooling for boxless pouring on the workbench 1;

[0089] S2. Sand mold modeling: Combine the product mold and the pouring system mold with the modeling sand, and take out the product mold and the pouring system mold after the modeling sand is solidified to form the product shape and the cavity sand mold of the pouring system;

[0090] S3, core making: filling the product core box with molding sand, pounding it, splitting the core box, and obtaining the mud core 9;

[0091] S4, alloy liquid smelting: after melting the alloy ingot and the master alloy, add the refining agent, the refiner and the covering agent into the molten liquid in proportion, stir and degas until the chemical composition is qualified;

[0092] S5, processing the seams on the mud core 9 on the workbench 1 and applying paint;

[0093] S6, combine the sand mold 15 and the mud core 9, and confirm that the cavity gap between the inner wall of the sand mold and the outer wall of the mud core meets the size requirements of the drawing;

[0094] S7, performing boxless casting on the workbench 1, injecting the alloy liquid into the mold cavity, and performing sand cleaning after cooling and molding to obtain a casting 19 with a pouring and rigging system;

[0095] S8, removing the pouring system on the casting 19 and polishing the appearance of the casting 19;

[0096] S9, performing solution heat treatment on the casting 19;

[0097] S10, performing rotational extrusion shaping on the casting 19, so that the casting 19 reaches a casting state within a dimensional tolerance range;

[0098] S11, placing the casting 19 into an aging furnace for aging treatment.

[0099] like Figures 1 to 4 As shown, the tooling for boxless casting in S1 includes a square horizontal bottom plate 3 fixed above the workbench 1, and the four corners of the horizontal bottom plate 3 are respectively screwed with bottom plate adjustment screws 3d, and the tops of the bottom plate adjustment screws 3d are respectively provided with circular ring ears. A circular bottom plate countersunk hole 3a is provided at the center of the horizontal bottom plate 3, and a bottom plate center hole 3b is provided at the center of the bottom countersunk hole. A platform rotating cover 5 is supported on the bottom wall of the bottom plate countersunk hole 3a through a plane bearing 4. Due to the slow rotation speed, the plane bearing 4 can be replaced by a steel ball embedded in an annular groove; an adjustment motor 2 is installed at the bottom center of the workbench 1, and the upper end of the output shaft of the adjustment motor 2 can pass through the bottom plate center hole 3b and be connected to the bottom wall center of the platform rotating cover 5.

[0100] The horizontal bottom plate 3 is provided with slider grooves 3c symmetrically located around the platform rotating cover 5, and sliders 6 are respectively embedded in the slider grooves 3c. The outer sides of the sliders 6 are respectively connected with rotatable slider adjustment screws 6c, and the threaded sections of the slider adjustment screws 6c are respectively screwed into the screw holes of the horizontal bottom plate 3. When the slider adjustment screws 6c are screwed in or out, the inner ends of the slider adjustment screws 6c rotate on the outer sides of the sliders 6 and pull the sliders 6 to slide in the slider grooves 3c, so as to adjust the distance between the sliders 6 and the axis of the platform rotating cover 5.

[0101] A slider groove 6a is provided at the center of the top of each slider 6, and two slider positioning pins 6b are provided on the bottom wall of the slider groove 6a.

[0102] S5 includes the following sub-steps:

[0103] S5.1. Fix the mud core 9 on the platform rotating cover 5 and keep them coaxial. The chassis can be fixed on the platform rotating cover 5, and the mud core 9 is fixed in the chassis. The chassis can match the mud core 9. When assembling the sand mold, a larger chassis can be replaced, or a chassis matching the sand mold 15 can be directly used, which is convenient for direct assembly in the subsequent process.

[0104] S5.2. An adjusting vertical rod 7 is fixed on each slider 6. An adjusting vertical rod embedding groove 7a extending vertically is provided on the inner side of each adjusting vertical rod 7. The cross section of the adjusting vertical rod embedding groove 7a is dovetail-shaped and opens toward the axial direction of the platform rotating cover 5.

[0105] The bottom sides of each adjusting vertical rod 7 are provided with adjusting vertical rod bosses 7b, which are fixed to the top of the slider 6 by adjusting vertical rod fixing screws 7c. The slider 6 is embedded in the slider embedding groove 3c of the horizontal bottom plate 3, and the two side walls of each slider 6 and the slider embedding groove 3c form a sliding pair. The middle of each slider 6 is provided with a slider sink groove 6a, and the bottom wall of the slider sink groove 6a is provided with two positioning pins 6b. The lower end of the adjusting vertical rod 7 is embedded in the slider sink groove 6a to obtain positioning, and the two positioning pins 6b are respectively inserted into the positioning holes at the bottom of the adjusting vertical rod 7 to obtain double positioning. After the bottom of the adjusting vertical rod 7 is accurately positioned on the slider 6, the adjusting vertical rod boss 7b is fastened to the slider 6 by the adjusting vertical rod fixing screws 7c to achieve fixed connection.

[0106] S5.3. Insert the scraper blades 8 extending vertically into the adjusting vertical rod grooves 7a respectively, and the scraper blade dovetail tenon 8a at the root of each scraper blade 8 matches the adjusting vertical rod groove 7a; by rotating the slider adjusting screw 6c, the active surfaces of each scraper blade 8 are on the same circumference with the mud core axis as the center, and are respectively fitted on the circumference of the mud core 9.

[0107] like Figure 3 , Figure 4 As shown, during installation, it is only necessary to insert the scraper blade dovetail tenon 8a downward from the upper end of the adjusting vertical rod groove 7a. Through the cooperation of the scraper blade dovetail tenon 8a and the dovetail groove, the scraper blade 8 and the adjusting vertical rod 7 can be accurately matched and locked with each other, and the scraper blade dovetail tenon 8a will not be separated from the dovetail groove during operation; the upper part of the scraper blade 8 is provided with a coating cavity 8c extending vertically downward, the top of the coating cavity 8c is closed, and the upper part of the active surface of the scraper blade 8 is provided with a coating flow outlet 8d, and the inner end of the coating flow outlet 8d is communicated with the upper part of the coating cavity 8c; the top of the scraper blade 8 is close to the scraper blade dovetail tenon 8a. A coating injection port 8b is provided, and the inner end of the coating injection port 8b extends downward and is communicated with the bottom of the coating cavity 8c.

[0108] S5.4, adjust the output shaft of the motor 2 to slowly drive the platform rotating cover 5 to rotate at a speed of 30-50rpm, the platform rotating cover 5 drives the mud core 9 to rotate, the plane bearing 4 bears the weight of the platform rotating cover 5 and makes the rotation very light and flexible; while the mud core 9 rotates, the scraper blades 8 on the four phases are respectively trimming the outer peripheral wall of the mud core 9 until no false sand falls. Then the paint is injected into the paint injection port 8b through the air pipe, the paint first flows downward, enters the lower part of the paint cavity 8c from the bottom connecting port of the paint cavity 8c, then flows upward along the paint cavity 8c, and finally flows out from the upper paint outflow port 8d, adjust the pressure, let the paint flow downward against the action surface of the scraper blade, while the mud core 9 rotates, the paint is evenly scraped on the outer wall of the mud core, and the entire mud core circumference is scraped by the rotation. It not only ensures the cylindricality of the mud core 9, but also reduces the friction between the scraper blade 8 and the mud core 9, eliminating the subsequent process of painting.

[0109] S7 includes the following sub-steps:

[0110] S7.1, if Figures 5 to 8 As shown, the adjusting motor 2 is installed away from the axis of the platform rotating cover, and a sleeve 10 is screwed into the center hole of the platform rotating cover 5. The lower part of the sleeve 10 is a belt driving end 10a, which is connected to the output end of the adjusting motor 2 through a belt 2a.

[0111] S7.2. Insert the riser tube 11 into the inner cavity of the insert sleeve 10, and provide two rows of balls 12 between the outer periphery of the riser tube 11 and the inner wall of the insert sleeve 10. The top outlet of the riser tube 11 is connected to the gate 15a at the lower end of the sand mold 15. Semicircular grooves can be processed on the inner wall of the insert sleeve 10 and the outer wall of the riser tube 11, respectively, and holes can be punched on the riser tube 11. After several balls 12 are inserted into the corresponding grooves, the holes can be closed.

[0112] S7.3. Insert the sand mold backing plates 14 into the adjusting vertical rod embedding grooves 7a respectively. The roots of the sand mold backing plates 14 are respectively embedded in the adjusting vertical rod embedding grooves 7a through the backing plate dovetail tenons 14a. By rotating the slider to adjust the screw 6c, the inner side surfaces of the sand mold backing plates 14 are respectively tangent to the outer walls of the sand mold 15, thereby limiting the outer periphery of the sand mold 15 to prevent it from being skewed.

[0113] S7.4, the riser pipe 11 remains stationary, and the sleeve 10 supported on the outer periphery of the riser pipe 11 by the ball 12 can rotate relatively. The adjusting motor 2 drives the sleeve 10 to rotate slowly through the belt 2a. The sleeve 10 drives the platform rotating cover 5 and the sand mold 15 to rotate at a speed of 30-50rpm. At the same time, the alloy liquid is injected into the mold cavity through the riser pipe 11. Wait for the time specified by the process. After the alloy liquid is cooled, a casting 19 and a pouring system are formed.

[0114] S7.5, if Figures 9 to 11As shown, each adjustment vertical rod 7 is removed, and an adjustment frame 13 is fixed on each slider 6. A through adjustment frame vertical slot 13a is provided along the height direction of the adjustment frame 13. A plurality of positioning blocks 16 are installed along the height direction of the adjustment frame vertical slot 13a. Positioning block tenons 16a are provided on both sides of each positioning block 16. Positioning block tenons 16a are respectively embedded in the horizontal embedded slots 13b of the side walls of the adjustment frame vertical slot 13a. The lower end of each adjustment frame 13 is respectively embedded in the corresponding slider sink groove 6a, and the slider positioning pin 6b is respectively inserted into the positioning hole at the bottom of the adjustment frame 13; the bottom of each adjustment frame 13 is respectively provided with an adjustment frame boss 13c, and the adjustment frame boss 13c is fixed to the top of the slider 6 by the adjustment frame fixing screw 13d.

[0115] S7.6. Insert the sleeve 17 into the inner port of the center hole of each positioning block, plug and fix the cutter 18 into the inner port of the center hole of the sleeve, and the cutter 18 abuts against the outer wall of the sand mold 15.

[0116] S7.7, the motor 2 is adjusted again to drive the platform rotating cover 5 to rotate at a speed of 40-60 rpm, and the slider adjusting screw 6c is manually shaken to make the slider 6 gradually move inward. After each cutter 18 cuts the sand mold 15 into several sections, the sand is manually cleaned and the casting 19 with the pouring system is taken out.

[0117] S8 includes the following sub-steps:

[0118] S8.1. Use a sawing machine to saw off the pouring and rigging system connected to the casting 19;

[0119] S8.2, turning the outer circle of the casting 19 by a lathe;

[0120] S8.3. Measure the dimensions of casting 19 and visually inspect its appearance for casting defects according to the drawings;

[0121] S8.4. Inspect castings for internal defects by X-ray and fluorescence.

[0122] S8.5. Weld repairs shall be performed on the parts with internal defects exceeding the standard detected by X-ray and fluorescence inspection;

[0123] S8.6. Lathe the welded parts of the casting.

[0124] S9 includes the following sub-steps:

[0125] S9.1, if Fig.12 , Fig.13 As shown, the casting 19 is placed stably on the solid solution base plate 29. A solid solution base plate center hole 29a is provided at the center of the solid solution base plate 29. The arc blocks 29b on the upper end surface of the solid solution base plate 29 are evenly abutted against the outer side of the lower end of the casting 19. Four arc blocks 29b can be evenly provided along the same circumference to facilitate the embedding of the lower end of the casting 19 and directly obtain accurate positioning.

[0126] S9.2, insert the lower end of each limiting tube 31 into the bottom plate plugging countersunk holes 29c evenly distributed on the outer periphery of the solid solution bottom plate 29, each bottom plate plugging countersunk hole 29c is provided with a radial limiting block 29d, and the bottom of each limiting tube 31 is provided with a radial embedding groove 31a, which is clamped on the corresponding radial limiting block 29d to achieve mutual positioning and limit the rotation of the limiting tube 31. The limiting tubes 31 are evenly arranged, and eight can be provided.

[0127] S9.3. A circular gland 30 is placed above the casting 19. The upper end of each limiting tube 31 passes through the guide hole 30a of the circular gland 30. The side wall of each limiting tube 31 is tangent to the outer periphery of the casting 19, and the outer periphery of the casting 19 is uniformly limited to adapt to the draft taper of the casting 19. The casting 19 maintains roundness during the solution process and reduces its deformation; the axial direction of each limiting tube 31 can be freely extended and retracted in the guide hole 30a of the circular gland 30.

[0128] S9.4. Screw an upper nut 33a onto each of the two long fixed screws 32 and rotate them to the top. Insert the two long fixed screws 32 symmetrically into the gland screw mounting holes 30b on the circular gland 30, and pass through the inner cavity of the casting and out from the base plate screw mounting holes 29e.

[0129] S9.5. Screw the lower nut 33b on the lower end of the fixed long screw 32 and press it on the lower end surface of the solid solution bottom plate 29, and keep the lifting rings 32a at the top of the two fixed long screws 32 at the same height, then screw the upper nut 33a downward and press it on the upper end surface of the circular gland 30, so that the circular gland 30 and the solid solution bottom plate 29 are connected as a whole, which is convenient for lifting; the upper end of each limit tube 31 remains in a floating state;

[0130] S9.6. Pass the steel wire rope through the lifting ring 32a, lift the solid solution tooling as a whole, and put it into the oven for heating and insulation. Since the locking force and material of the heat treatment tooling have a certain influence on the aluminum alloy, and the tissue medium will undergo transformation during the heat treatment of the casting 19, in order not to affect the transformation of the tissue medium, after many experimental verifications, the limit tube 31 uses a 0Cr297Ni9Ti stainless steel tube with a wall thickness of 32mm. After secondary annealing treatment, a steel tube with a heat treatment hardness close to that suitable for the aluminum alloy casting 19 is obtained, which effectively eliminates the obstacles to the transformation of the tissue medium during the solid solution.

[0131] S9.7. After the heat preservation is completed, the solid solution tooling is hoisted as a whole and placed in a 60-80℃ water pool for rapid cooling for 10 minutes before being taken out. Since the limiting tube 31 is tangent to the casting 19 and only has line contact, when the casting 19 is immersed in water for cooling, the area that is not in contact with the water is very small, which does not affect the rapid and uniform cooling of the whole. During the cooling process, each limiting tube 31 still limits the outer wall of the casting 19, so that it continues to maintain a very high roundness.

[0132] S10 includes the following sub-steps:

[0133] S10.1. Remove the sleeves 17 and cutters 18 in the positioning blocks 16 on the adjustment frame 13.

[0134] S10.2, if Figures 14 to 17 As shown, the roller rod 22 is inserted into the center hole of the positioning block from the rear end, and the fork at the front end of the roller rod 22 extends from the front end of the center hole of the positioning block. The roller shaft and the roller 23 are installed between the forks of each roller rod, and the roller 23 is fixed between the forks of the roller rod through the roller shaft.

[0135] S10.3. Insert the spring 24 and the limiting rod 25 into the center hole of the positioning block from the rear end in sequence, with the front end of the spring 24 resting on the roller rod boss, and the rear end of the spring 24 resting on the inner end surface of the limiting rod 25.

[0136] S10.4, the digital display rod 26 is respectively fitted and fixed on the outside of each adjustment frame 13, and the upper and lower ends of the digital display rod 26 are fixedly connected to the adjustment frame 13 by screws. A plurality of digital display rod mounting holes are respectively provided on the digital display rod 26 along the height direction, and a sensing screw seat 28 is respectively screwed into each digital display rod mounting hole, and a sensing sheet 27 is respectively installed on the side of each sensing screw seat 28 facing the adjustment frame 13, and each sensing sheet 27 is respectively against the outer end of the corresponding limit rod 25.

[0137] S10.5. Since the size of the platform rotating cover 5 cannot be changed, when processing castings 19 with different outer diameters, the matching tray 20 can be accurately processed according to the outer dimensions of the casting 19. The bottom of the tray 20 is fixedly connected to the platform rotating cover 5 through eight bolt holes and achieves precise coaxiality.

[0138] S10.6. The lower end of the casting 19 is embedded in the tray 20. The outer edge of the tray 20 is provided with an annular vertical edge that stands upright. Multiple radial screws 21 are evenly screwed along the circumference of the annular vertical edge to fix the bottom of the casting 19. The annular vertical edge of the outer edge of the tray 20 is precisely clamped on the outer edge of the lower end of the casting 19 so that the casting 19 and the tray 20 are concentrically positioned, so that when the platform rotating cover 5 rotates, the casting 19 can accurately achieve coaxial rotation. The inner end of each radial screw 21 clamps the outer periphery of the bottom of the casting 19 to prevent the casting 19 from rotating during shaping.

[0139] S10.7, by adjusting the induction screw seat 28, the distances between the four induction plates 27 and the axis of the casting 19 on the same circumference are equal;

[0140] S10.8. The motor 2 is adjusted to drive the casting 19 to rotate. The four rollers 23 at each height perform rotational extrusion and shaping on the casting 19 so that the roundness of the casting 19 meets the tolerance requirements.

[0141] The casting 19 is still in a soft state after solution treatment. When rotating, the outer wall of the casting 19 contacts the rollers 23. The high points of the circumference of the casting 19 are squeezed by the rollers 23 and gradually become round. The squeezing force of the rollers 23 is transmitted to the sensing sheets 27 through the limit rods 25. The pressure of each sensing sheet 27 is displayed on the screen of the elastic tester. If the pressure error of the four rollers 23 on the same circumference is within the set tolerance range, it means that the roundness of the circumference has met the requirements.

Claims

1. A flaskless casting method for manufacturing thin-walled rotating aluminum alloy castings, characterized in that: The steps include: S1. Install the tooling for boxless pouring on the workbench; S2. Sand mold modeling: Combine the product mold and the pouring system mold with the modeling sand, and take out the product mold and the pouring system mold after the modeling sand is solidified to form the product shape and the cavity sand mold of the pouring system; S3, core making: fill the product core box with modeling sand, pound it, split the core box and get the mud core; S4, alloy liquid smelting; S5. Process the seams on the mud core and apply paint on the workbench; S6. Combine the sand mold and the clay core to confirm that the cavity gap between the inner wall of the sand mold and the outer wall of the clay core meets the size requirements of the drawing; S7, perform boxless pouring on the workbench, inject the alloy liquid into the mold cavity, and perform sand cleaning after cooling and molding to obtain a casting with a pouring system; S8. Remove the pouring system on the casting and polish the appearance of the casting; S9, performing solution heat treatment on the casting; S10, performing rotational extrusion shaping on the casting so that the casting reaches a casting state within a dimensional tolerance range; S11, placing the casting into an aging furnace for aging treatment; The tooling for boxless casting described in S1 comprises a horizontal bottom plate fixed on a workbench, a circular bottom plate countersunk hole is provided at the center of the horizontal bottom plate, a bottom plate center hole is provided at the center of the bottom plate countersunk hole, a platform rotating cover is supported on the bottom wall of the bottom plate countersunk hole through a plane bearing, and an adjusting motor for driving the platform rotating cover to rotate is installed at the bottom center of the workbench; the horizontal bottom plate is provided with slider embedding grooves symmetrically located around the platform rotating cover, sliders are respectively embedded in the slider embedding grooves, and rotatable slider adjusting screws are respectively connected to the outer sides of each slider, and the threaded sections of each slider adjusting screw are respectively screwed into the screw holes of the horizontal bottom plate; a slider sink groove is provided at the center of the top of each slider, and a slider positioning pin is provided on the bottom wall of the slider sink groove; S5 includes the following sub-steps: S5.

1. Fix the mud core on the platform rotating cover and keep it coaxial; S5.

2. An adjusting vertical rod is fixed on each slider, and an adjusting vertical rod embedding groove extending vertically is provided on the inner side of each adjusting vertical rod. The cross section of the adjusting vertical rod embedding groove is dovetail-shaped and opens toward the axial direction of the platform rotating cover; S5.

3. Insert scraper blades extending vertically into the grooves of the vertical adjustment rods respectively, and the dovetail tenon at the root of each scraper blade matches the groove of the vertical adjustment rod; rotate the slider to adjust the screw rod so that the active surface of each scraper blade fits on the circumference of the mud core respectively; S5.

4. Drive the rotating cover of the platform to rotate at a speed of 30-50rpm until no false sand falls off; then inject paint to the top of each scraper blade near the top of the dovetail through the air pipe. The paint first reaches the bottom of the paint cavity downward, then reaches the upper part of the paint cavity upward, flows out from the upper part of the scraper blade action surface and is smeared on the outer wall of the mud core.

2. The flaskless casting method for manufacturing thin-walled rotating aluminum alloy casting according to claim 1, characterized in that: In S4, after the alloy ingot and the master alloy are melted, the refining agent, the refiner and the covering agent are added to the molten liquid in proportion, and the mixture is stirred and degassed until the chemical composition is qualified.

3. The flaskless casting method for manufacturing thin-walled rotating aluminum alloy casting according to claim 1, characterized in that: In S5.2, the lower end of each adjusting vertical rod is respectively embedded in the corresponding slider groove, and the slider positioning pin is respectively inserted into the positioning hole at the bottom of the adjusting vertical rod; adjusting vertical rod bosses are respectively provided on both sides of the bottom of each adjusting vertical rod, and the adjusting vertical rod bosses are fixed to the top of the slider by adjusting vertical rod fixing screws.

4. The flaskless casting method for manufacturing thin-walled aluminum alloy rotating body casting according to claim 1, characterized in that: S7 includes the following sub-steps: S7.

1. Screw a sleeve into the center hole of the platform rotating cover, wherein the lower part of the sleeve is a belt driving end, and the belt driving end is connected to the output end of the regulating motor through a belt; S7.2, inserting a liquid riser into the inner cavity of the insert sleeve, two balls are arranged between the outer periphery of the liquid riser and the inner wall of the insert sleeve, and the top outlet of the liquid riser is connected to the gate at the lower end of the sand mold; S7.

3. Insert the sand mold support plates into the grooves of the adjusting vertical rods respectively. The roots of the sand mold support plates are respectively embedded in the grooves of the adjusting vertical rods through dovetail tenons. The inner side surfaces of the sand mold support plates are respectively tangent to the outer wall of the sand mold by rotating the slider to adjust the screw rod. S7.

4. Adjust the motor to drive the platform rotating cover to rotate at a speed of 30-50 rpm, and inject the alloy liquid into the cavity through the liquid riser. After the alloy liquid is cooled, a casting and a pouring system are formed; S7.

5. Remove each adjustment vertical rod, fix the adjustment frame on each slider, provide a continuous adjustment frame vertical slot along the height direction of the adjustment frame, install a plurality of positioning blocks along the height direction of the adjustment frame vertical slot, and provide positioning block tenons on both sides of each positioning block, and the positioning block tenons are respectively embedded in the horizontal embedding grooves on the side walls of the adjustment frame vertical slot; S7.

6. Insert a sleeve into the inner port of the center hole of each positioning block, and plug and fix the cutter into the inner port of the center hole of the sleeve; S7.

7. The motor is adjusted again to drive the platform rotating cover to rotate at a speed of 40-60rpm. At the same time, the slider is manually adjusted by shaking the screw rod to make the slider gradually move inward. After each cutter cuts the sand mold, the sand is manually cleaned and the casting with the pouring system is taken out.

5. The flaskless casting method for manufacturing thin-walled rotating aluminum alloy casting according to claim 4, characterized in that: In S7.5, the lower end of each adjustment frame is respectively embedded in the corresponding slider groove, and the slider positioning pins are respectively inserted into the positioning holes at the bottom of the adjustment frame; adjustment frame bosses are respectively provided on both sides of the bottom of each adjustment frame, and the adjustment frame bosses are fixed to the top of the slider by the adjustment frame fixing screws.

6. The flaskless casting method for manufacturing thin-walled rotating aluminum alloy casting according to claim 1, characterized in that: S8 includes the following sub-steps: S8.

1. Remove the runner system connected to the casting by sawing. S8.2, turning the outer diameter of the casting by lathe; S8.

3. Measure the dimensions of the castings according to the drawings and visually inspect the appearance for casting defects; S8.

4. Inspect castings for internal defects by X-ray and fluorescence. S8.

5. Weld repairs shall be performed on the parts with internal defects exceeding the standard detected by X-ray and fluorescence inspection; S8.

6. Lathe the welded parts of the casting.

7. The flaskless casting method for manufacturing thin-walled aluminum alloy rotating body casting according to claim 1, characterized in that: S9 includes the following sub-steps: S9.

1. Place the casting steadily on the solid solution bottom plate, and the arc blocks on the upper surface of the solid solution bottom plate evenly abut against the outer side of the lower end of the casting; S9.

2. Insert the lower end of each limiting tube into the bottom plate plugging countersunk holes evenly distributed on the outer periphery of the solid solution bottom plate, each bottom plate plugging countersunk hole is provided with a radial limiting block, and the bottom of each limiting tube is provided with a radial embedding groove clamped on the corresponding radial limiting block; S9.

3. Place a circular gland on the casting, the upper end of each stopper tube passes through the guide hole of the circular gland, and the side wall of each stopper tube is tangent to the outer periphery of the casting; S9.

4. Screw an upper nut onto each of the two long fixed screws and rotate them to the top. Insert the two long fixed screws symmetrically into the gland screw mounting holes on the circular gland, and pass through the inner cavity of the casting and out of the base plate screw mounting holes. S9.

5. Screw the lower nut on the lower end of the fixed long screw and press it on the lower end surface of the solid solution bottom plate, and keep the lifting rings on the top of the two fixed long screws at the same height. Then screw the upper nut downward and press it on the upper end surface of the circular gland, so that the circular gland and the solid solution bottom plate are connected as a whole and the upper ends of each limit tube remain in a floating state; S9.

6. Pass the steel wire rope through the lifting ring, lift the solid solution tooling as a whole, and put it into the oven for heating and heat preservation; S9.

7. After the insulation is completed, lift the solution treatment tooling as a whole and put it into a 60-80℃ water pool for rapid cooling for 10 minutes before taking it out.

8. The flaskless casting method for manufacturing thin-walled rotating aluminum alloy casting according to claim 4, characterized in that: S10 includes the following sub-steps: S10.

1. Remove the sleeves and cutters from the positioning blocks on the adjustment frame; S10.

2. Insert the roller rod from the rear end into the center hole of the positioning block. The fork head at the front end of the roller rod extends from the front end of the center hole of the positioning block. Install the roller shaft and the roller between the forks of the roller rods. S10.

3. Insert the spring and the limit rod into the center hole of the positioning block from the rear end in sequence, with the front end of the spring resting on the roller rod boss and the rear end of the spring resting on the inner end surface of the limit rod; S10.

4. A digital display rod is fitted and fixed on the outside of each adjustment frame. A plurality of digital display rod mounting holes are respectively provided on the digital display rod in the height direction. A sensing screw seat is screwed into each digital display rod mounting hole. A sensing sheet is respectively installed on the side of each sensing screw seat facing the adjustment frame. Each sensing sheet is respectively against the outer end of the corresponding limit rod; S10.

5. Fix the pre-processed tray matching the casting coaxially above the platform rotating cover; S10.

6. The lower end of the casting is embedded in a tray. The outer edge of the tray is provided with an annular vertical edge standing upright. Multiple radial screws are evenly screwed along the circumference of the annular vertical edge to fix the bottom of the casting; S10.

7. Adjust the induction screw seat to make the distances between the four induction plates on the same circumference and the axis of the casting equal; S10.

8. The motor is adjusted to drive the casting to rotate. Four rollers at different heights rotate, extrude and shape the casting so that the roundness of the casting meets the tolerance requirements.

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