WO2023240806A1 - Stepless-adjustment efficient additive manufacturing method and device for specially shaped rotary body sand mold - Google Patents

Abstract

A stepless-adjustment efficient additive manufacturing device for a specially shaped rotary body sand mold, the device comprising an aluminum alloy frame (1), and an ink jet system, a shakeout device, a sand scraping device and a Z-axis rotary lifting movement system, which are arranged on the aluminum alloy frame. In the device, quantitative shakeout and uniform sand spreading are implemented on a rotary printing platform by keeping a shakeout box (7), a printing nozzle (3) and a sand scraping plate fixed, and the rotary printing platform can descend accurately and controllably by means of a ball screw (21) device, thereby spreading sand layer by layer and performing printing layer by layer; in addition, the height by which the rotary platform descends is adjusted steplessly, and resin saturation between molding sand particles is adjusted according to a micro-droplet jet printing grayscale, thereby improving the overall printing speed and strength of a sand mold. Further disclosed is a stepless-adjustment efficient additive manufacturing method for a specially shaped rotary body sand mold. The device achieves, with stepless heightwise adjustment, 3D printing of a specially shaped rotary body sand mold. When manufacturing specially shaped rotary bodies, the specially shaped rotary body sand mold has a high forming efficiency and can manufacture specially shaped rotary bodies with a good quality; in addition, the process cost and waste are reduced.

Description

A method and device for stepless adjustment and high-efficiency additive manufacturing of special-shaped rotary body sand molds Technical field

The invention relates to the field of 3D printing, specifically a stepless adjustment and efficient additive manufacturing method and device for a special-shaped rotary body sand mold.

Background technique

As a basic manufacturing process for the equipment manufacturing industry, sand casting is widely used in equipment manufacturing industries such as aerospace and power machinery. It is in urgent need of digitalization, greening and high-performance transformation and upgrading. Combined with modern digital manufacturing technology, the integration of resin sand casting technology and 3D printing technology has become the main direction for the future development of the foundry industry. As a technology and equipment suitable for small batches, high-end complex parts manufacturing and new product development, sand 3D printing technology and equipment has brought disruptive changes to the foundry industry. The development of this technology will help realize the intelligent upgrading of the company's casting industry, further improve casting production capacity and product quality, and enhance the company's core competitiveness. Sand 3D printing mold manufacturing has a short production cycle, low cost, and can add more functionality to mold design improvements.

Traditional special-shaped rotary sand molds are made using a mold-turning process. Manual processing requires multiple profiling processes and assembly and jointing. The dimensional accuracy of the sand mold is poor and the processing dimensional accuracy of the parts cannot be guaranteed. Nowadays, special-shaped rotary bodies with wall thickness and shape and size that meet the requirements can be obtained through CNC machine tool processing, but the experimental operation is complicated and causes a waste of material resources; special-shaped rotary body castings can be obtained by turning some traditional molds over the shape and pouring, but other Molds have problems such as high processing difficulty, low yield, and low performance of cast castings.

Therefore, there is an urgent need to design a molding device and method for special-shaped rotary body sand molds that can solve the above technical problems and enable rapid prototyping.

Contents of the invention

In order to solve the problems of complex manufacturing of special-shaped rotary bodies, low forming efficiency and poor precision, as well as high costs and waste of resources in some processes, the present invention provides a stepless adjustment and efficient additive manufacturing method and device for special-shaped rotary body sand molds.

In order to achieve the above objects, the technical solutions adopted by the present invention are:

A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds, including an aluminum alloy frame, which is arranged on the aluminum alloy frame:

The inkjet system includes an ink pressure sensor, a printing nozzle, a nozzle drive board, a nozzle accessory mounting plate, and a pressure sensor mounting plate. The nozzle accessory mounting plate and the pressure sensor mounting plate are installed on the aluminum alloy profile. The nozzle drive board is installed on the nozzle accessory installation. On the board, the ink pressure sensor is installed on the pressure sensor mounting plate, the printing nozzle is installed on the sanding and nozzle mounting plate, the printing nozzle is connected to the nozzle drive board, and the nozzle drive board is connected to the ink pressure sensor;

The shakeout device includes a shakeout box, a number of shakeout ports provided on the shakeout box, a control switch and a stepper motor a for controlling the opening and closing of the shakeout port. The control switch is installed in the shakeout box. The box and stepper motor a are installed on the sand spreading and nozzle mounting plate, and the sand spreading and nozzle mounting plate are fixed on the aluminum alloy frame;

The sand scraping device consists of a short scraper and a long scraper, and is fixedly installed on the underside of the sand spreading and nozzle installation plate;

The Z-axis rotational lifting motion system is divided into a Z-axis lifting system and a rotation system. The Z-axis lifting system includes a sand box bottom plate, a cylindrical lifting slide, a support guide column, a bearing seat, a lifting guide column, a sealing lifting plate, and a ball wire. Rod, screw nut, lift motor base, synchronous belt, stepper motor b, bottom plate, screw heightening support, pulley a and pulley b. The bottom plate of the sand box is cylindrical, with a through hole drilled in the middle, and the through hole is It is equipped with a bearing seat, and four counterbores are processed directly below the countersunk hole of the sealed lifting plate. The countersunk hole is equipped with a guide column bearing, directed upward, and is used to connect the lifting guide column. Four countersunk holes are processed on the lower side of the aluminum alloy plate. It is used to connect the support guide pillars; the lifting slide is a rectangular parallelepiped, with a through hole processed in the middle part, and a screw nut is installed in the through hole, used to connect the ball screw, and is processed at the corresponding position below the four countersunk holes on the bottom plate of the sand box. There are four through holes. The through holes are equipped with guide column bearings. The bearing seat is directed downward and are used to connect the support guide columns. There are 4 countersunk holes processed below the counterbore holes processed in the sealing lifting plate for connection. lifting guide column;

The base plate is a rectangular parallelepiped, and four countersunk holes are processed below the through holes processed by the lifting slide for connecting the support guide posts. The screw heightening support is fixedly connected to the middle of the base plate through screw bolts, and the pulley b is fixedly connected to the ball screw, and the ball screw is fixed on the screw heightening support; the lifting motor seat is located on one side of the screw heightening support and is fixedly connected to the base plate through bolts. The stepper motor b is equipped with a pulley. a, the pulley on the ball screw is connected through a synchronous belt b; the rotary motion system includes a sealed lifting plate, a stepper motor c, a central control rotating platform, a rotating table, a triangular table, and balls; the middle part of the rotating table is fixedly connected by bolts The control rotating platform, the stepper motor c 28 is fixedly connected to the sealed lifting plate through bolts, the central control rotating platform is fixedly connected to the sealed lifting plate through bolts, the stepper motor c is connected through a helical gear, and the triangular stage is fixedly connected to the sealed lifting plate On the machine, the ball is located between the triangular table and the rotary table to support and assist the movement of the rotary table.

Further, the control switch is a semicircle, and the stepper motor a is used to rotate the control switch to open and close the sand falling port.

Further, one end of the short scraper and the long scraper is located at the center of the seal lift plate. The length of the long scraper is the radius of the seal lift plate and is located behind the sand dropout in the direction of rotation. The length of the short scraper is the radius of the seal lift. Half of the radius of the plate is located on the front side of the sand dropout in the direction of rotation.

Furthermore, the sand falling opening is designed in a fan shape, which is beneficial to the uniform sand falling on the rotating table.

Further, it also includes a cylindrical wall installed on the bottom plate of the sand box, with a thickness of 2 cm.

Further, the rotary table is cylindrical and consists of two upper and lower cylindrical aluminum alloy plates and a cylindrical resin plate fixedly installed between the two cylindrical aluminum alloy plates by bolts. The outer side of the cylindrical aluminum alloy plate is separated from the side plate of the sand box 2cm, and the cylindrical aluminum alloy plate on the lower side is processed with a semicircular slide.

Further, the number of the triangular tables is 4, and the upper end is processed with a circular groove for placing the balls.

The invention also provides a stepless adjustment and high-efficiency additive manufacturing method for special-shaped rotary body sand molds, which is manufactured using the device as claimed in the claims, including the following steps:

Step 1: Set different slice thicknesses according to the design requirements of the special-shaped rotary body sand mold, and slice the designed special-shaped rotary body into unequal thickness slices to obtain two-dimensional special-shaped rotary body layers with different thicknesses;

Step 2: Control the stepper motor b to drive pulley a to rotate. Pulley a drives pulley b to rotate through the synchronous belt. Pulley b drives the screw to rotate. The screw nut converts the rotational motion of the screw into The lifting slide moves up and down in the Z-axis direction. The lifting slide controls the up and down movement of the sealing lifting plate through the lifting guide pillar. The sealing lifting plate drives the rotating table to move down 1mm through the central control rotating platform to prevent resin penetration when printing the first layer. Go to the rotary table to corrode the rotary table;

Step 3: Pre-pave raw sand on the rotating table and control the rotation of the rotating table. When the rotating table rotates one circle, the raw sand will be spread;

Step 4: Fill the sand shakeout box with molding sand mixed with curing agent, turn on the stepper motor a rotation control switch to shake out the sand, and control the printing nozzle according to the two-dimensional The image and rotation speed are sprayed to match the grayscale resin, the rotary table rotates once, the current slice thickness is reduced, and printing is repeated until the entire sand mold printing is completed, and all stepper motors are turned off;

Step 5: Wait for a while, remove the waste sand, and take out the sand mold.

Furthermore, the descending speed of the rotary table is automatically adjusted according to the current layer thickness.

The invention has the following beneficial effects:

1) By fixing the scraper and controlling the rotation of the rotary table, sand can be spread quickly and evenly;

2) By fixing the shakeout box and nozzle, controlling the rotation of the rotary table to achieve special-shaped rotary body sand molding, reducing the movement of the nozzle and reducing the loss of the nozzle; at the same time, by controlling the switch in the shakeout box, the shakeout can be easily adjusted The amount of falling sand can be easily adjusted;

3) This equipment can be equipped with three printing nozzles, which increases the printing speed; by continuously adjusting the lowering speed of the rotary table and the matching rotation speed, the matching printing grayscale is adjusted according to the lowering speed of the rotary table, further improving the printing speed;

4) This equipment is used to manufacture special-shaped rotary sand molds, which are easy to operate and control, have high precision and are easy to form.

Description of the drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings:

Figure 1 is a schematic structural diagram of a stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds according to an embodiment of the present invention;

Figure 2 is a schematic structural diagram of the sand spreading device and inkjet system in the embodiment of the present invention;

Figure 3 is a schematic structural diagram of the Z-axis lifting and rotating motion in the embodiment of the present invention;

Figure 4 is a schematic diagram of the Z-axis lifting motion structure in Figure 4;

Figure 5 is a schematic diagram of the rotational motion structure in Figure 4;

Figure 6 is a cross-sectional view at C in Figure 6;

Figure 7 is a schematic diagram of the structure and position of the scraper in the embodiment of the present invention;

Figure 8 is a front view of position A in Figure 2;

Figure 9 is a cross-sectional view at B in Figure 2.

In the picture: 1. Aluminum alloy frame; 2. Nozzle accessory mounting plate; 3. Printing nozzle; 4. Pressure sensor mounting plate; 5. Ink pressure sensor; 6. Sand spreading and nozzle mounting plate; 7. Shaking out box; 8 , Stepper motor a; 9. Cylindrical wall; 10. Sealed lifting plate; 11. Lifting guide column; 12. Bearing seat; 13. Lead screw nut; 14. Stepper motor b; 15. Lifting motor base; 16. Pulley a; 17. Base plate; 18. Timing belt; 19. Screw heightening support; 20. Pulley b; 21. Ball screw; 22. Support guide column; 23. Lifting slide table; 24. Guide column bearing ; 25. Triangular stage; 26. Rotary stage; 27. Central control rotating platform; 28. Stepper motor c; 29. Ball; 30. Short scraper; 31. Long scraper; 32. Nozzle drive plate; 33. Control switch.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example 1

As shown in Figures 1 to 8, a special-shaped rotary body sand mold stepless adjustment and high-efficiency additive manufacturing device includes an aluminum alloy frame 1, which is arranged on the aluminum alloy frame 1:

The inkjet system includes an ink pressure sensor 5, a printing nozzle 3, a nozzle drive board 32, a nozzle accessory mounting plate 2, a pressure sensor mounting plate 4, a nozzle accessory mounting plate 2 and a pressure sensor mounting plate 4 installed on an aluminum alloy profile 1 through threads On the top, the nozzle drive board is installed on the nozzle accessory mounting plate 2 through bolts, the ink pressure sensor 5 is installed on the pressure sensor mounting plate 4 through bolts, the printing nozzle 3 is installed on the sand laying and nozzle mounting plate 6 through threads, and the printing nozzle 3 Connect the nozzle driving board 32, and the nozzle driving board 32 is connected to the ink pressure sensor 5;

The shakeout device includes a shakeout box 7, a number of shakeout ports provided on the shakeout box, a control switch 33 for controlling the opening and closing of the shakeout port, and a stepper motor a 8. The control switch 33 is a semicircle and is installed In the shakeout box 7, the control switch is rotated by the stepper motor a to open and close the shakeout port. The shakeout box 7 and the stepper motor a8 are installed on the sand spreading and nozzle mounting plate 6. The sand spreading and nozzle The mounting plate 6 is fixed on the aluminum alloy frame 1; the sand falling port is designed in a fan shape, which is conducive to uniform sand falling on the rotating table;

The sand scraping device consists of a short scraper 30 and a long scraper 31, which are fixedly installed on the lower side of the sand spreading and nozzle installation plate 6; one end of the short scraper 30 and the long scraper 31 is located at the center of the sealing lift plate, and the long scraper The length of the plate 31 is the radius of the sealing lifting plate and is located on the rear side of the sand dropout in the rotation direction. The length of the short scraper 30 is half the radius of the sealing lift plate and is located on the front side of the sand dropout in the rotation direction;

The Z-axis rotating lifting motion system is divided into a Z-axis lifting system and a rotating system. The Z-axis lifting system realizes the precise lifting of the sealed lifting plate through a ball screw structure. The rotating system drives the central control rotating platform through a motor to realize the rotating table. Rotary motion; among them, the Z-axis lifting system includes the bottom plate of the sand box, the cylindrical lifting slide 23, the supporting guide column 22, the bearing seat 12, the lifting guide column 11, the sealing lifting plate 10, the ball screw 21, the screw nut 13, the lifting Motor base 15, synchronous belt 18, stepper motor b 14, base plate 17, screw heightening support 19, pulley a 16 and pulley b 20, a cylindrical wall 9 with a thickness of 2cm is installed on the bottom plate of the sand box. The bottom plate of the box is cylindrical, with a through hole drilled in the middle. The through hole is equipped with a bearing seat 12. There are four counterbores located directly below the counterbored hole of the sealing lifting plate 10. The counterbored hole is equipped with a guide post bearing 24 with the direction upward. , used to connect the support guide column 11, and 4 countersunk holes are processed on the lower side of the aluminum alloy plate for connecting the lifting guide column 22; the lifting slide table 23 is a rectangular parallelepiped, with a through hole processed in the middle part, and the screw nut 13 is installed in the through hole. It is used to connect the ball screw 21. Four through holes are processed at the corresponding positions below the four counterbore holes on the bottom plate of the sand box. The through holes are equipped with guide pillar bearings 24. The bearing seat is directed downward and is used to connect the supporting guide pillars. 22. There are 4 countersunk holes processed below the countersunk holes processed in the sealed lifting plate for connecting the lifting guide pillar 11;

The bottom plate 17 is a rectangular parallelepiped, and four countersunk holes are processed below the through holes processed by the lifting slide for connecting the support guide posts 22. The screw heightening support 19 is connected to the middle of the bottom plate 17 through screw bolts. position, the pulley b 20 is fixedly connected to the ball screw 21, and the ball screw 21 is fixed to the screw heightening support 19; the lifting motor base 15 is located on one side of the screw heightening support, and is fixedly connected to the base plate through bolts. , the stepper motor b 14 is equipped with a pulley a 16, which is connected to the pulley b 20 on the ball screw 21 through a synchronous belt 18; the rotary motion system includes a sealed lifting plate 10, a stepper motor c 28, a central control rotating platform 27, The rotary table 26, the triangular table 25, and the balls 29; the middle part of the rotary table 26 is connected to the central control rotating platform 27 through bolts, the stepper motor c 28 is connected to the sealed lifting plate 10 through bolts, and the central control rotating platform 27 is fixed through bolts It is connected to the sealing lifting plate 10 and connected to the stepper motor c 28 through a helical gear. The triangular table 25 is fixedly connected to the sealing lifting plate 10. The ball 29 is located between the triangular table 25 and the rotating table 26 for supporting and assisting the rotating table 26. sports. The rotating table 26 is cylindrical and consists of two upper and lower cylindrical aluminum alloy plates and a cylindrical resin plate fixedly installed between the two cylindrical aluminum alloy plates by bolts. The outer side of the cylindrical aluminum alloy plate is 2cm away from the side plate of the sand box. And the cylindrical aluminum alloy plate on the lower side is processed with a semi-circular slideway.

In this embodiment, the number of the triangular tables is 4, and the upper end is processed with a circular groove for placing the balls. Preferably, the number of triangular stages can be increased to make the rotation movement of the rotary stage smoother.

In this embodiment, the scraper can be designed as a roller, which is beneficial to rolling and compacting the sand mold and improving the overall performance of the sand mold.

Example 2

A stepless adjustment and high-efficiency additive manufacturing method for special-shaped rotary body sand molds, manufactured using the device described in Embodiment 1, including the following steps:

Step 1: Set different slice thicknesses according to the design requirements of the special-shaped rotary body sand mold, and slice the designed special-shaped rotary body into unequal thickness slices to obtain two-dimensional special-shaped rotary body layers with different thicknesses;

Step 2: Control the stepper motor b to drive pulley a to rotate. Pulley a drives pulley b to rotate through the synchronous belt. Pulley b drives the screw to rotate. The screw nut converts the rotational motion of the screw into The lifting slide moves up and down in the Z-axis direction. The lifting slide controls the up and down movement of the sealing lifting plate through the lifting guide pillar. The sealing lifting plate drives the rotating table to move down 1mm through the central control rotating platform to prevent resin penetration when printing the first layer. Go to the rotary table to corrode the rotary table;

Step 3: Pre-pave raw sand on the rotating table and control the rotation of the rotating table. When the rotating table rotates one circle, the raw sand will be spread;

Step 4: Fill the sand shakeout box with molding sand mixed with curing agent, turn on the stepper motor a rotation control switch to shake out the sand, and control the printing nozzle according to the two-dimensional The image and rotation speed are sprayed to match the grayscale resin, the rotary table rotates once, the current slice thickness is reduced, and printing is repeated until the entire sand mold printing is completed, and all stepper motors are turned off;

Step 5: Wait for a while, remove the waste sand, and take out the sand mold.

In this embodiment, the descending speed of the rotary table can be automatically adjusted according to the current layer thickness.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above. Those skilled in the art can make various variations or modifications within the scope of the claims, which does not affect the essence of the present invention.

Claims (9)

1. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds, which is characterized in that it includes an aluminum alloy frame, and is arranged on the aluminum alloy frame:

   The inkjet system includes an ink pressure sensor, a printing nozzle, a nozzle drive board, a nozzle accessory mounting plate, and a pressure sensor mounting plate. The nozzle accessory mounting plate and the pressure sensor mounting plate are installed on the aluminum alloy profile. The nozzle drive board is installed on the nozzle accessory installation. On the board, the ink pressure sensor is installed on the pressure sensor mounting plate, the printing nozzle is installed on the sanding and nozzle mounting plate, the printing nozzle is connected to the nozzle drive board, and the nozzle drive board is connected to the ink pressure sensor;

   The shakeout device includes a shakeout box, a number of shakeout ports provided on the shakeout box, a control switch and a stepper motor a for controlling the opening and closing of the shakeout port. The control switch is installed in the shakeout box. The box and stepper motor a are installed on the sand spreading and nozzle mounting plate, and the sand spreading and nozzle mounting plate are fixed on the aluminum alloy frame;

   The sand scraping device consists of a short scraper and a long scraper, and is fixedly installed on the underside of the sand spreading and nozzle installation plate;

   The Z-axis rotational lifting motion system is divided into a Z-axis lifting system and a rotation system. The Z-axis lifting system includes a sand box bottom plate, a cylindrical lifting slide, a support guide column, a bearing seat, a lifting guide column, a sealing lifting plate, and a ball wire. Rod, screw nut, lift motor base, synchronous belt, stepper motor b, bottom plate, screw heightening support, pulley a and pulley b. The bottom plate of the sand box is cylindrical, with a through hole drilled in the middle, and the through hole is It is equipped with a bearing seat, and four counterbores are processed directly below the countersunk hole of the sealed lifting plate. The countersunk hole is equipped with a guide column bearing, directed upward, and is used to connect the lifting guide column. Four countersunk holes are processed on the lower side of the aluminum alloy plate. It is used to connect the support guide pillars; the lifting slide is a rectangular parallelepiped, with a through hole processed in the middle part, and a screw nut is installed in the through hole, used to connect the ball screw, and is processed at the corresponding position below the four countersunk holes on the bottom plate of the sand box. There are four through holes. The through holes are equipped with guide column bearings. The bearing seat is directed downward and are used to connect the support guide columns. There are 4 countersunk holes processed below the counterbore holes processed in the sealing lifting plate for connection. lifting guide column;

   The base plate is a rectangular parallelepiped, and four countersunk holes are processed below the through holes processed by the lifting slide for connecting the support guide posts. The screw heightening support is fixedly connected to the middle of the base plate through screw bolts, and the pulley b is fixedly connected to the ball screw, and the ball screw is fixed on the screw heightening support; the lifting motor seat is located on one side of the screw heightening support and is fixedly connected to the base plate through bolts. The stepper motor b is equipped with a pulley. a, the pulley on the ball screw is connected through a synchronous belt b; the rotary motion system includes a sealed lifting plate, a stepper motor c, a central control rotating platform, a rotating table, a triangular table, and balls; the middle part of the rotating table is fixedly connected by bolts The control rotating platform, the stepper motor c 28 is fixedly connected to the sealed lifting plate through bolts, the central control rotating platform is fixedly connected to the sealed lifting plate through bolts, the stepper motor c is connected through a helical gear, and the triangular stage is fixedly connected to the sealed lifting plate On the machine, the ball is located between the triangular table and the rotary table to support and assist the movement of the rotary table.
2. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds according to claim 1, characterized in that the control switch is a semicircle, and the control switch is rotated by a stepper motor a to open the sand falling port. with closure.
3. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds as claimed in claim 1, characterized in that one end of the short scraper and the long scraper is at the center of the sealing lifting plate, and the length of the long scraper is The radius of the lifting plate is located on the back side of the sand dropout in the rotation direction. The length of the short scraper is half the radius of the sealing lift plate and is located on the front side of the sand dropout in the rotation direction.
4. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds according to claim 1, characterized in that the sand falling port is designed in a fan shape, which is conducive to uniform sand falling on the rotating table.
5. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds according to claim 1, characterized in that it also includes a cylindrical wall installed on the bottom plate of the sand box, with a thickness of 2 cm.
6. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds as claimed in claim 1, characterized in that the rotating table is cylindrical and consists of two upper and lower cylindrical aluminum alloy plates and two cylindrical plates fixed by bolts. There is a cylindrical resin plate between the cylindrical aluminum alloy plates. The outer side of the cylindrical aluminum alloy plate is 2cm away from the side plate of the sand box, and the cylindrical aluminum alloy plate on the lower side is processed with a semicircular slideway.
7. A stepless adjustment and high-efficiency additive manufacturing device for special-shaped rotary body sand molds as claimed in claim 1, characterized in that the number of the triangular tables is 4, and the upper end is processed with a circular groove for placing balls.
8. A stepless adjustment and high-efficiency additive manufacturing method for special-shaped rotary body sand molds, which is characterized in that it is manufactured using the device according to any one of claims 1-7, including the following steps:

   Step 1: Set different slice thicknesses according to the design requirements of the special-shaped rotary body sand mold, and slice the designed special-shaped rotary body into unequal thickness slices to obtain two-dimensional special-shaped rotary body layers with different thicknesses;

   Step 2: Control the stepper motor b to drive pulley a to rotate. Pulley a drives pulley b to rotate through the synchronous belt. Pulley b drives the screw to rotate. The screw nut converts the rotational motion of the screw into The lifting slide table moves up and down in the Z-axis direction. The lifting slide table controls the up and down movement of the sealing lifting plate through the lifting guide column. The sealing lifting plate drives the rotating table to move down by 1mm through the central control rotating platform;

   Step 3: Pre-pave raw sand on the rotating table and control the rotation of the rotating table. When the rotating table rotates one circle, the raw sand will be spread;

   Step 4: Fill the sand shakeout box with molding sand mixed with curing agent, turn on the stepper motor a rotation control switch to shake out the sand, and control the printing nozzle according to the two-dimensional The image and rotation speed are sprayed to match the grayscale resin, the rotary table rotates once, the current slice thickness is reduced, and printing is repeated until the entire sand mold printing is completed, and all stepper motors are turned off;

   Step 5: Wait for a while, remove the waste sand, and take out the sand mold.
9. A stepless adjustment and high-efficiency additive manufacturing method for special-shaped rotary body sand molds as claimed in claim 8, characterized in that the descending speed of the rotary table is automatically adjusted according to the current layer thickness.

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