Multi-material point-by-point voxel coplanar additive manufacturing method and apparatus

Abstract

This invention relates to a multi-material voxel coplanar additive manufacturing method and apparatus, including a printer housing, a printer bracket, a sand spreader, a sand storage tank, a sand spreading arm, a sand spreading pen, a sand spreading pen magazine, and a multi-material recycling tank. This invention divides the designed mold into multiple regions, slicing them and assigning different material labels. During powder spreading, the sand spreader first spreads a layer of molding sand, the main material, onto the printing platform; then, the sand spreading arm drives the sand spreading pen to remove excess molding sand in the second material region, and spreads the required material molding sand; after the second material region is finished, the excess material in the sand spreading pen and its pipeline is discharged, and the sand spreading arm drives the sand spreading pen to perform suction and discharge in the third material region; this process continues until the material is laid in the printing area. This invention's apparatus and method enable rapid, integrated forming of multi-material sand molds (cores), achieving multi-functional, multi-gradient, and high-performance sand mold (core) manufacturing.

Description

Technical Field

[0001] This invention relates to the field of sand-based additive manufacturing, and more particularly to a multi-material point-by-point voxel coplanar forming additive manufacturing method and apparatus. Background Technology

[0002] Sand mold additive manufacturing technology involves spraying a binder onto the molding site, where physical changes and chemical reactions bind powder materials together, layer by layer, to form a shaped part. However, most current sand mold additive manufacturing processes involve forming a single material. Multi-material powder layering typically only achieves material variations between different layers or simply divides a single layer into different areas for different materials. It cannot achieve precise placement of multiple materials in arbitrary shapes and locations, or in minute areas, nor can it realize the complex sand mold forming of multifunctional, multi-gradient, or composite materials. Current multi-material sand layering devices and methods suffer from the following problems:

[0003] (1) It cannot achieve single-layer multi-material laying; the materials can only be replaced when laying a new layer.

[0004] (2) When laying multiple materials in a single layer, it is only possible to lay the second material in a large area of ​​a simple shape, but it is not possible to form a multi-material laying with complex shapes and fine structures.

[0005] (3) The device is complex and not flexible enough to operate. Summary of the Invention

[0006] To address the aforementioned issues, this invention discloses a multi-material point-by-point voxel coplanar forming additive manufacturing method and apparatus, which enables flexible and accurate multi-material laying and the manufacture of complex sand molds for multi-functional, multi-gradient, and composite materials.

[0007] A multi-material point-by-point voxel coplanar additive manufacturing method and apparatus includes a printer housing that protects the internal structure; a freely height-adjustable printing platform; a printing nozzle for spraying adhesive; a sand spreader for laying the main material; a sand spreader arm and a sand spreader pen for laying the remaining materials; a recycling tank and a multi-material recycling tank for recovering excess materials; and a sand storage tank and a multi-material sand storage tank for providing materials.

[0008] Furthermore, the sand-spreading arm can drive the sand-spreading pen to move and rotate in the x, y, and z directions, and its range of motion covers the entire printing platform, recycling tank, multi-material recycling tank, and sand-spreading pen library. The sand-spreading arm has two pipes inside: one for adding sand and the other for sucking up and discharging waste sand. An ultrasonic vibrator is installed in the sand-adding pipe near the sand-spreading pen to assist in sand spreading.

[0009] Furthermore, the sand storage tank is used to store the molding sand of the main material, and the bottom has a pipeline connected to the sand spreading trough of the sand spreader; the sand spreader is mainly composed of a sand spreading trough, a sand spreading roller and a sand spreader frame, integrating sand spreading, compaction and leveling functions.

[0010] Furthermore, the sand-spreading pen has two internal channels, corresponding to the sand-spreading port and sand-returning port at the pen tip. The sand-spreading port provides molding sand and auxiliary sand spreading through a vacuum sand feeder and an ultrasonic vibrator. The sand-returning port removes excess molding sand through a vacuum sand feeder. The sand-spreading pen and the sand-spreading port and sand-returning port come in various shapes and sizes to suit different working conditions. The sand-spreading pen and the sand-spreading arm are fixed by mechanical and electric locking. The positioning threads on the sand-spreading pen are used to ensure that the internal channels of the sand-spreading pen and the channels in the sand-spreading arm correspond correctly.

[0011] Furthermore, the sanding pen magazine is protected by a pen magazine protective door to isolate the tool from the external environment. The pen magazine protective door is only opened when the sanding pen is replaced. Inside the sanding pen magazine, there is a sanding pen slot, and inside the sanding pen slot, there is an electric slot for storing sanding pens of different models.

[0012] Furthermore, the multi-material sand storage tank is mainly divided into upper and lower parts. The upper part is a multi-material sand storage tank, which is used to store molding sand of different materials. A gravity sensor is installed in the tank to monitor the amount of sand in the tank and the amount of sand added each time. Each tank is equipped with an electromagnetic switch. The lower part is a sand mixing zone. When multiple materials need to be mixed, materials of different proportions are placed in the sand mixing zone, and high-pressure airflow is introduced through the air vent to mix the different materials evenly. The multi-material sand storage tank transports sand to the sand supply pipeline of the sand spreading arm through a vacuum sand feeder.

[0013] A multi-material point-by-point voxel coplanar forming additive manufacturing method and apparatus, characterized in that the method includes the following steps:

[0014] Step 1: Based on the three-dimensional digital model of the casting, design the three-dimensional digital model of the sand mold, divide it into multiple regions, and perform layered slicing and assign different material labels (slice thickness: 0.3mm~1mm adjustable), and transmit the sliced ​​data to the control system;

[0015] Step 2: Return all moving parts to the zero position, and feed sand into the sand spreader from the sand storage tank;

[0016] Step 3: The sand spreader first lays the main material molding sand on the printing platform and scrapes the excess molding sand into the recycling tank;

[0017] Step 4: The sand spreading arm drives the sand spreading pen to move in the second material area. The sand spreading pen's return port sucks up the first type of material molding sand and discharges it into the multi-material return sand trough. Then, with the support of the multi-material sand storage tank supplying the second type of material molding sand and the ultrasonic vibrator, the sand spreading port begins to spread the second type of material molding sand.

[0018] Step 5: After the second type of material sand is laid, the sand-laying arm moves the sand-laying pen to the multi-material recycling tank to drain the excess second type of material from the pipe. The sand-laying roller then scrapes the sand layer on the printing platform smooth again.

[0019] Step 6: Repeat steps 4 and 5 to lay the remaining materials in the corresponding areas;

[0020] Step 7: After the sand layer is laid, the print head sprays adhesive at the desired forming position. After the adhesive is sprayed, the printing platform lowers by one layer thickness.

[0021] Step 8: Repeat steps 3 to 7 until the sand mold printing is complete;

[0022] Step 9: Raise the printing platform to the top, clean up the loose sand, and remove the sand mold;

[0023] Step 10: Shut down the machine.

[0024] Furthermore, the materials include not only molding sand, but also ceramic powder, metal powder, plastic, nylon, etc.

[0025] Furthermore, the minimum wall thickness of the remaining material laid by the sand-spreading pen in step 4 should be ≥0.5mm. The sand-spreading pen varies in vacuum degree of sand absorption and discharge, moving speed, and thickness of penetration into the sand layer depending on the material and the thickness of the sand layer.

[0026] Furthermore, when the sanding arm needs to replace the sanding pen in step 4, the sanding arm places the currently mounted sanding pen into the corresponding sanding pen slot, and the electric locking slot locks the sanding pen. The electric locking slot on the sanding arm releases the sanding pen, rotates one revolution, and removes the sanding pen. Then, it moves to the position of the sanding pen that needs to be installed, and the new sanding pen can be installed by operating in the reverse order of the above steps.

[0027] The beneficial effects of this invention are:

[0028] This invention enables flexible and accurate laying of various materials, not only for large-scale, multi-area laying of different materials, but also for laying of small-scale, complex curved surfaces and variable-sized geometric shapes. It can form complex sand molds with multiple materials, multiple gradients, and composite materials. Furthermore, it features various sand-laying pens to meet requirements under different working conditions, improving laying efficiency and accuracy. The multi-material sand storage tank can not only store multiple materials but also achieve uniform mixing of different materials in different proportions, further expanding the range of materials that can be used. Based on this invention, the combination of a robotic arm and sand-laying pens for sand suction and laying, the multi-material sand storage tank and sand-feeding device, the pen library providing various types of sand-laying pens, and the sand mold forming method, it is possible to achieve the forming and printing of multiple materials at any position on the sand mold, realizing the forming of sand molds with multi-material structural interaction, complex geometric shapes, multiple gradients, and functions. Attached Figure Description

[0029] Figure 1 This is an overall view of the equipment of the present invention;

[0030] Figure 2 This is a front view of the internal structure of the equipment of the present invention;

[0031] Figure 3 Left view of the internal structure of the equipment of this invention;

[0032] Figure 4 This is a top view of the sand spreader of the present invention;

[0033] Figure 5 This is a schematic diagram of the sand-laying pen magazine of the present invention;

[0034] Figure 6 This is a schematic diagram of the multi-material sand storage tank of the present invention;

[0035] Figure 7 This is a cross-sectional view of the multi-material sand storage tank of the present invention;

[0036] Figure 8 This is a schematic diagram of a sanding pen according to the present invention;

[0037] Figure 9 This is a flowchart illustrating the implementation of the present invention.

[0038] List of reference numerals in the attached diagram:

[0039] 1-Printer housing, 2-Printer bracket, 3-Sand storage tank, 4-Sand spreader, 401-Sand spreading trough, 402-Sand spreading roller, 403-Sand spreader outer frame, 5-Sand spreading arm, 6-Sand spreading pen, 601-Sand spreading port, 602-Sand return port, 603-Positioning thread, 7-Sand spreading pen magazine, 701-Pen magazine protective door, 702-Sand spreading pen trough, 8-Multi-material recycling tank, 9-Printing platform, 10-Recycling tank, 11-Multi-material sand storage tank, 1101-Air hole, 1102-Multi-material sand storage trough, 1103-Sand mixing area, 1104-Gravity sensor, 1105-Electromagnetic switch, 12-Vacuum sand feeder, 13-Printing nozzle, 14-Sliding guide rail. Detailed Implementation

[0040] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0041] Figure 1 , Figure 2 and Figure 3The diagram shown is a schematic representation of the overall appearance and internal structure of a multi-material point-by-point voxel coplanar additive manufacturing apparatus according to this embodiment. It mainly includes a printer housing 1, a printer bracket 2, a sand storage tank 3, a sand spreader 4, a sand spreading arm 5, a sand spreading pen 6, a sand spreading pen magazine 7, a multi-material recycling tank 8, a printing platform 9, a recycling tank 10, a multi-material sand storage tank 11, a vacuum sand spreader 12, a printing nozzle 13, and a sliding guide rail 14.

[0042] The sand-spreading arm 5 can drive the sand-spreading pen 6 to move and rotate in the x, y, and z directions, and its range of motion covers the entire printing platform 9, recycling tank 10, multi-material recycling tank 8, and sand-spreading pen magazine 7. The sand-spreading arm 5 has two pipes inside, one for adding sand and the other for sucking up and discharging waste sand. The sand-adding pipe is equipped with an ultrasonic vibrator 501 near the sand-spreading pen 6 to assist the sand-spreading pen 6 in spreading sand.

[0043] The sand storage tank 3 is used to store the main materials, and the bottom has a pipe connected to the sand spreading trough 401 of the sand spreading device 4; the sand spreading device is mainly composed of the sand spreading trough 401, the sand spreading roller 402 and the sand spreading device frame 403, which integrates the functions of sand spreading, compaction and leveling.

[0044] The sand-spreading pen 6 has two internal pipes, corresponding to the sand-spreading port 601 and the sand-returning port 602 at the tip. The sand-spreading pen 6 and the sand-spreading port 601 and the sand-returning port 602 come in various shapes and sizes to suit different working conditions. The sand-spreading pen 6 and the sand-spreading arm 5 are fixed by mechanical and electric engagement. The positioning thread 603 on the sand-spreading pen 6 is used to ensure that the internal pipes of the sand-spreading pen 6 correspond correctly to the pipes in the sand-spreading arm 5.

[0045] The minimum wall thickness of the remaining material laid by the sand-spreading pen 6 should be ≥0.5mm. The vacuum degree of sand suction and discharge, moving speed, and penetration depth of the sand layer vary depending on the material and the thickness of the sand layer.

[0046] The sanding pen magazine 7 is protected by a pen magazine protective door 701, which isolates the tool from the external environment. The pen magazine protective door 701 is only opened when the sanding pen 6 is replaced. Inside the sanding pen magazine 7 is a sanding pen slot 702, which has an electric slot for holding different models of sanding pens 6.

[0047] When the sanding arm 5 needs to replace the sanding pen 6, the sanding arm 5 places the currently mounted sanding pen 6 into the corresponding sanding pen slot 702, and the electric slot locks the sanding pen 6. The electric slot on the sanding arm 5 releases the sanding pen 6, rotates one revolution, and removes the sanding pen 6. Then it moves to the position of the sanding pen 6 that needs to be installed. The new sanding pen 6 can be installed by reversing the above steps.

[0048] The multi-material sand storage tank 11 is mainly divided into two parts: the upper part is a multi-material sand storage tank 1102, which is used to store different materials. A gravity sensor 1104 is installed in the tank to monitor the amount of sand in the tank and the amount of sand added each time. Each tank is equipped with an electromagnetic switch 1105. The lower part is a sand mixing zone 1103. When multiple materials need to be mixed, materials of different proportions are placed in the sand mixing zone 1103. High-pressure airflow is introduced through the air hole 1101 to mix the different materials evenly. The multi-material sand storage tank 11 transports sand to the sand supply pipeline of the sand spreading arm 5 through the vacuum sand feeder 12.

[0049] The method and apparatus of this invention can not only form various molding sand materials, but also ceramic powder, metal powder, plastic, nylon and other materials.

[0050] The present invention provides a multi-material point-by-point voxel coplanar additive manufacturing method, the implementation steps of which are as follows:

[0051] Step 1: Based on the three-dimensional digital model of the casting, design the three-dimensional digital model of the sand mold, divide it into multiple regions, and perform layered slicing and assign different material labels (slice thickness: 0.3mm~1mm adjustable), and transmit the sliced ​​data to the control system;

[0052] Step 2: Return all moving parts to the zero position, and fill the sand storage tank 3 with sand for the sand spreader 4;

[0053] Step 3: The sand spreader 4 first spreads the main material molding sand on the printing platform 9 and scrapes the excess molding sand into the recycling tank 10;

[0054] Step 4: The sand spreading arm 5 drives the sand spreading pen 6 to move in the second material area. The sand spreading pen return port 602 sucks up the first type of material molding sand and discharges it into the multi-material recycling tank 8. Then, with the second type of material molding sand supplied by the multi-material sand storage tank 11 and the assistance of the ultrasonic vibrator, the sand spreading port 601 begins to spread the second type of material molding sand.

[0055] Step 5: After the second type of material sand is laid, the sand laying arm 5 moves the sand laying pen 6 to the multi-material recycling tank 8 to clean up the excess second type of material in the pipe, and the sand laying roller 402 scrapes the sand layer on the printing platform 9 again.

[0056] Step 6: Repeat steps 4 and 5 to lay the remaining materials in the corresponding areas;

[0057] Step 7: After the sand layer is laid, the printing nozzle 13 sprays adhesive at the desired forming position. After the adhesive is sprayed, the printing platform drops by one layer thickness.

[0058] Step 8: Repeat steps 3 to 7 until the sand mold printing is complete;

[0059] Step 9: Raise the printing platform to the top, clean up the loose sand, and remove the sand mold;

[0060] Step 10: Shut down the machine.

[0061] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A multi-material point-by-point voxel coplanar additive manufacturing apparatus, comprising a printer housing (1), a printer bracket (2), a sand storage tank (3), and a sand spreader (4); characterized in that: It also includes a sand-spreading arm (5), a sand-spreading pen (6), a sand-spreading pen magazine (7), a multi-material recycling tank (8), a printing platform (9), a recycling tank (10), a multi-material sand storage tank (11), a vacuum sander (12), a print head (13), and a sliding guide rail (14); the recycling tank (10) is installed on the side wall of the printing platform (9); the printer bracket (2) is equipped with a sliding guide rail (14) for the sand-spreading device (4) to move and spread sand; the print head (13) is installed on the sand-spreading device (4) and can move on the sand-spreading device (4); the sand-spreading pen magazine (7) is installed on the inner side wall of the printer housing (1); the sand-spreading arm (5) is installed on the inner side wall of the printer housing (1) and is opposite to the sand-spreading pen magazine (7); Inside the printer housing (1), a sand storage tank (3) and a multi-material sand storage tank (11) are respectively installed on the top. The multi-material recycling tank (8) is placed below the sand spreading arm (5). The bottom of the sand spreading arm (5) is connected to the sand spreading pen (6). The sand spreading arm (5) can drive the sand spreading pen (6) to move and rotate in the x, y and z directions. Its range of motion covers the entire printing platform (9), recycling tank (10), multi-material recycling tank (8) and sand spreading pen library (7). The sand spreading arm (5) has two pipes inside, one for sanding and the other for sucking up and discharging waste sand. The sanding pipe is equipped with an ultrasonic vibrator (501) near the sand spreading pen (6) to assist the sand spreading pen (6) in spreading sand. The sand storage tank (3) is used to store the main sand. The molding sand for the material is connected to the sand spreading groove (401) of the sand spreading device (4) by a pipe at the bottom; the sand spreading device consists of a sand spreading groove (401), a sand spreading roller (402) and a sand spreading device frame (403), integrating sand spreading, compaction and leveling functions; the sand spreading pen (6) is divided into two pipes inside, corresponding to the sand spreading port (601) and sand return port (602) opened at the tip of the pen; the sand spreading port (601) provides molding sand and auxiliary sand spreading through the vacuum sand feeder (12) and the ultrasonic vibrator (501); the sand return port (602) removes excess molding sand through the vacuum sand feeder (12); the sand spreading pen (6) and the sand spreading port (601) and the sand return port (602) have various shapes and sizes to adapt to different working conditions. The sand-spreading pen (6) and the sand-spreading arm (5) are fixed by mechanical and electric clamping. The positioning thread (603) on the sand-spreading pen (6) is used to position the internal pipeline of the sand-spreading pen (6) and the pipeline in the sand-spreading arm (5) to correspond correctly. The multi-material sand storage tank (11) is divided into two parts, the upper part is a multi-material sand storage tank (1102), which is used to store molding sand of different materials. A gravity sensor (1104) is installed in the tank to monitor the amount of sand in the tank and the amount of sand added each time. Each tank is equipped with an electromagnetic switch (1105). The lower part is a sand mixing area (1103). When multiple materials need to be mixed, materials of different proportions are placed in the sand mixing area (1103). High-pressure airflow is introduced through the air hole (1101) to mix the different materials evenly.The multi-material sand storage tank (11) delivers sand to the sand supply pipeline of the sand-laying arm (5) via a vacuum sand feeder (12).

2. The multi-material point-by-point voxel coplanar additive manufacturing apparatus according to claim 1, characterized in that: The sanding pen magazine (7) is protected by a pen magazine protective door (701) to isolate the tool from the external environment. The pen magazine protective door (701) is only opened when the sanding pen (6) is replaced. The sanding pen magazine (7) has a sanding pen slot (702) inside, and an electric slot is inside the sanding pen slot (702) to hold different types of sanding pens (6).

3. A multi-material point-by-point voxel coplanar additive manufacturing method, based on the multi-material point-by-point voxel coplanar additive manufacturing apparatus according to any one of claims 1-2, characterized in that, The method includes the following steps: Step 1: Based on the three-dimensional digital model of the casting, design the three-dimensional digital model of the sand mold, divide it into multiple regions, and perform layered slicing and assign different material labels. The slicing thickness is 0.3mm to 1mm. Transmit the slicing data to the control system. Step 2: Return all moving parts to the zero position, and feed sand to the sand spreader (4) from the sand storage tank (3); Step 3: Sand spreader (4) first spreads the main material molding sand on the printing platform (9) and scrapes the excess molding sand into the recycling tank (10); Step 4: The sand-spreading arm (5) drives the sand-spreading pen (6) to move in the second material area. The sand-spreading pen return port (602) sucks up the first type of material molding sand and discharges it into the multi-material recycling tank (8). Then, the sand-spreading port (601) starts to spread the second type of material molding sand with the assistance of the multi-material sand storage tank (11) and the ultrasonic vibrator. Step 5: After the second type of material sand is laid, the sand laying arm (5) moves the sand laying pen (6) to the multi-material recycling tank (8) to clean up the excess second type of material in the pipe, and the sand laying roller (402) scrapes the sand layer on the printing platform (9) again. Step 6: Repeat steps 4 and 5 to lay the remaining materials in the corresponding areas; Step 7: After the sand layer is laid, the printing nozzle (13) sprays adhesive at the desired forming position. After the adhesive is sprayed, the printing platform drops by one layer thickness. Step 8: Repeat steps 3 to 7 until the sand mold printing is complete; Step 9: Raise the printing platform to the top, clean up the loose sand, and remove the sand mold; Step 10: Shut down the machine.

4. The multi-material point-by-point voxel coplanar additive manufacturing method according to claim 3, characterized in that: The materials include not only molding sand, but also ceramic powder, metal powder, plastic, and nylon.

5. The multi-material point-by-point voxel coplanar additive manufacturing method according to claim 3, characterized in that: The minimum wall thickness of the remaining materials laid by the sand-spreading pen (6) in step 4 should be ≥0.5mm; the sand-spreading pen (6) has different vacuum degree, moving speed and thickness of sand penetration into the sand layer depending on different materials and sand layer thickness.

6. The multi-material point-by-point voxel coplanar additive manufacturing method according to claim 3, characterized in that: In step 4, when the sanding arm (5) needs to replace the sanding pen (6), the sanding arm (5) places the currently installed sanding pen (6) into the corresponding sanding pen slot (702), and the electric slot clamps the sanding pen (6). The electric slot on the sanding arm (5) releases the sanding pen (6), rotates one turn, removes the sanding pen (6), and then moves to the position of the sanding pen (6) that needs to be installed. The new sanding pen (6) can be installed by operating in the reverse order of the above steps.

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