Long-channel type concrete 3D printing nozzle printing system and printing method

Abstract

The application discloses a long-channel type concrete 3D printing nozzle printing system and a printing method. The system comprises a multi-nozzle printer group, at least one pumping machine for vibrating and pumping printing material in the inside to the multi-nozzle printer group to carry out 3D printing, and a controller. The application can liquefy the printing material through a vibrating rod at the pumping end, improve the printing material pumping efficiency through a multi-section type vibration-adjustable temperature pumping pipeline, reduce the risk of pipe blockage, reduce the interference of layer-jumping printing on the printed layer through an independently rotatable long-channel type printing nozzle, realize multi-material printing and non-horizontal extrusion, improve the lofting freedom degree during multi-model printing, and improve the utilization efficiency of the printing platform.

Description

Technical Field

[0001] This invention relates to the field of 3D printed concrete technology, and in particular to a long-channel concrete 3D printing nozzle printing system and printing method. Background Technology

[0002] Currently, most concrete 3D printing nozzles are inverted conical in shape, with the upper material hopper significantly larger than the printing extruder. This can easily cause the expanded upper hopper to collide with already printed areas during printing, interfering with the process. When printing multiple models simultaneously, this necessitates either single-layer skipping or increasing the distance between models. Single-layer skipping requires printing multiple components at the same horizontal height simultaneously, causing the printing strip for each model to break during each layer's ascent. This results in poor overall integrity between layers of the same printed entity, reduced aesthetics, decreased printing continuity, and increased demands on the printing material's performance. Increasing the placement distance between models significantly increases the space occupied by each printed model, thus reducing the number of simultaneous print jobs on the printing platform. Currently, multi-component printing is often achieved by increasing the number of 3D printing nozzles. However, these enlarged nozzles often occupy a large printing space and present difficulties in nozzle switching.

[0003] Currently, the most commonly used building printing materials are mortars with a fluidity of 180~200mm. In order to meet the requirements of construction, they are usually required to have good thixotropy and quickly lose fluidity when left to stand. This undoubtedly increases the difficulty of material pumping. On the printing site, even a short pause can often lead to pump pipe blockage.

[0004] 3D printed concrete has no formwork, and the printed strip has a large surface area in contact with air, resulting in rapid moisture loss. The later performance of the printed product is greatly affected by the ambient temperature and humidity. Generally speaking, as the temperature rises or the air becomes drier, the printing material hardens faster, and the material exhibits better buildability. Conversely, as the temperature drops and the air becomes humid, the printing material hardens slower, which is detrimental to the material's buildability. However, the improved buildability brought about by air drying is caused by the rapid water loss and drying of the printed strip, not by accelerating the hydration rate of the cementitious material, and will ultimately lead to the deterioration of the later performance of the printed product. Summary of the Invention

[0005] In view of this, the present invention provides a long-channel concrete 3D printing nozzle printing system and printing method. The present invention liquefies the printing material at the pumping end through a vibrating rod, improves the pumping efficiency of the printing material through a multi-segment vibrating and temperature-adjustable pumping pipeline, reduces the risk of pipe blockage, and reduces the interference of skip-layer printing on the already printed layers through an independently rotatable long-channel printing nozzle, realizing multi-material printing and non-horizontal extrusion.

[0006] A long-channel concrete 3D printing nozzle printing system includes a multi-nozzle printer assembly, at least one pump and controller for vibrating and conveying the printing material inside the assembly through a pumping pipe to the multi-nozzle printer assembly for 3D printing, the multi-nozzle printer assembly including a nozzle carrier mounted on a three-dimensional moving component of the concrete 3D printer, multiple mother disks mounted on the side of the nozzle carrier, and printing nozzles fixed on the mother disks and rotatable around the mother disks.

[0007] The pump hopper of the pump is equipped with a vibration mechanism to liquefy the printing material inside. The vibration mechanism is located above the stirring screw of the pump.

[0008] Preferably, the vibration mechanism includes vibration damping components fixed on two opposite walls of the pump hopper, a vibrating rod disposed between the two vibration damping components, and a transmission hose disposed in one of the vibration damping components and fixed to one end of the vibrating rod. The other end of the transmission hose passes through a locking hole on the wall of the pump hopper and is connected to the vibration motor. A sealing rubber ring is provided in the locking hole to seal the gap between the locking hole and the transmission hose to prevent printing material from overflowing.

[0009] Preferably, the vibration damping assembly includes a vibration damping spring, a vibration damping plate, and a bellows. One end of the vibration damping spring is fixed to the wall of the pump hopper, and the other end is fixed to the vibration damping plate. The bellows is sleeved on the outside of the vibration damping spring and the vibration damping plate.

[0010] Preferably, the sealing rubber ring includes a fixed outer ring in the shape of an annulus and a sealing inner ring vertically disposed in the center of the fixed outer ring and inserted into a card hole. The fixed outer ring is fixed to the hopper wall of the pump hopper by fasteners.

[0011] Preferably, the inner wall of the sealing inner ring has a "V" shaped cross-section in the axial direction, and its thickness in the radial direction gradually decreases from the middle to both sides.

[0012] Preferably, the print head includes a print head screw assembly and a silo assembly. The silo assembly includes a top plate and a bottom plate arranged in parallel, a base fixed to the print head carrier for connecting the top plate and the bottom plate, a silo fixed to the bottom plate with its upper port extending upward to the upper end face of the top plate, and a nozzle disposed at the lower end of the silo. The upper part of the silo is provided with a feed port for connecting to a pumping pipe. The lower part of the print head screw assembly is inserted downward into the silo and its upper part is fixed to the top plate.

[0013] Preferably, the nozzle screw assembly includes a nozzle motor, a reducer and coupling mounted on the nozzle motor, a nozzle screw connected to the output end of the nozzle motor, and a bearing disposed at the lower part of the nozzle screw. The bearing is mounted inside the silo to restrict the center of the nozzle screw to the center of the silo.

[0014] Preferably, the pumping pipe is composed of multiple pump pipe sections spliced ​​together, with a temperature-controlled water pipe wound around the outside of the pump pipe, and a vibration joint is provided at the end of the pump pipe connected to the discharge port of the pumping machine hopper and at the end of the pump pipe connected to each other.

[0015] Preferably, the three-dimensional moving component of the concrete 3D printer is provided with a temperature-controlled water pipe for spraying water mist onto the printing area.

[0016] A printing method for a long-channel concrete 3D printing nozzle printing system specifically includes the following steps:

[0017] S1, each printhead of the multi-head printer group is connected to a pump via a pumping pipe;

[0018] S2, respectively turn on the temperature-controlled water pipe on the pump pipe and the three-dimensional moving component of the concrete 3D printer;

[0019] S3: Add the required amount of printing material to each pump according to the printing needs, and adjust each pump so that the corresponding print head can stably extrude the printing material.

[0020] S4. According to the set printing sequence of the printing nozzles, the controller controls one of the pumps and its connected printing nozzles to start, making the printing nozzle vertically downward and the other printing nozzles vertically upward. The printing material in the pump is liquefied under the vibration of the vibration mechanism and enters the pump pipe from its outlet. It passes through the pump pipe, the inlet of the printing nozzle, the cylinder of the printing nozzle and the nozzle, and is extruded from the nozzle to perform the printing work. During the printing process, the printing nozzle follows its master disc to rotate according to the set printing path to dynamically adjust the direction of the printing material extruded from the nozzle of the printing nozzle. Under the drive of the three-dimensional moving component of the concrete 3D printer, it adjusts its printing layer. When the printing layer of the printing nozzle is finished, the controller controls another pump and its connected printing nozzle to start the printing work.

[0021] S5, after all printing layers have been printed, shut off the pump pipe and the temperature control water pipe on the three-dimensional moving component of the concrete 3D printer.

[0022] S6. Move the multi-head printer assembly out of the printing range and turn all the printheads vertically downwards. After squeezing out the remaining printing material in the printheads, clean the pump and the printhead screw assembly of the multi-head printer assembly.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention liquefies the printing material at the pumping end through a vibrating rod, improves the pumping efficiency of the printing material through a multi-segment vibrating and temperature-adjustable pumping pipeline, reduces the risk of pipe blockage, and reduces the interference of skip-layer printing on the already printed layers through an independent rotatable long-channel printing nozzle. It realizes multi-material printing and non-horizontal extrusion, improves the degree of freedom of layout when printing multiple models, and improves the utilization efficiency of the printing platform.

[0025] 2. The present invention adds a vibrating rod to the hopper of the pump, which vibrates the printing material in advance, so that the printing material is liquefied and compacted, improving pumping efficiency and reducing the risk of pipe blockage. At the same time, it avoids the damage to the printing head structure caused by adding a high-power vibrator in the printing head and avoids the reduction of printing accuracy.

[0026] 3. In this invention, the vibrating rod in the pump hopper is fixed inside the pump hopper by a damping spring, so that the vibration energy can be effectively applied to the printing material, reducing the absorption of vibration energy by the hopper. Furthermore, the damping spring is installed inside the bellows, which can prevent the printing material from affecting the damping effect of the spring.

[0027] 4. In this invention, the printing material in the long channel silo of the print head is extruded and printed under the pressure of the pump and the power of the print head screw assembly. Each print head can rotate independently with its own mother disc, which can realize non-horizontal extrusion of the print head. Changing the printing material in different print heads can also realize multi-material printing. In addition, the long cylindrical print head can also reduce the accumulation of excessive printing material in the print head, reduce the weight of the print head, and improve the print head conversion efficiency.

[0028] 5. By designing the pumping pipe as a multi-segment pumping pipeline and installing a vibration joint at the pump pipe joint, this invention can not only reduce the risk of pipe blockage when material conveying is paused and restarted, but also reduce the difficulty of maintaining the pump pipe blockage.

[0029] 6. This invention improves the adaptability of printing material to ambient temperature and humidity during pumping and printing by wrapping an adjustable temperature water pipe around the outside of the pumping pipe and setting a temperature-controlled water pipe on the three-dimensional moving component of the concrete 3D printer, thereby reducing the risk of pipe blockage and the requirements of the printing environment on the performance of the printing material.

[0030] 7. This invention is highly practical, its principle is easy to understand, its design is reasonable, it fully considers the disassembly and cleaning of pumping pipes and printing nozzles, it is highly usable, and it is convenient for production equipment. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the material feeding system.

[0033] Figure 2 This is a schematic diagram of a pump.

[0034] Figure 3 Top view of the pump Figure 1 .

[0035] Figure 4 Top view of the pump Figure 2 .

[0036] Figure 5 This is a schematic diagram of the pumping pipe.

[0037] Figure 6 This is a schematic diagram of a printhead.

[0038] Figure 7 This is a schematic diagram of the screw assembly.

[0039] Figure 8 This is a schematic diagram of a silo assembly.

[0040] Figure 9 This is a schematic diagram of the initial state of the dual-nozzle unit.

[0041] Figure 10 This is a schematic diagram of the dual-nozzle unit in operation.

[0042] Figure 11 This is a schematic diagram of the rubber clip hole.

[0043] Figure 12 This is a cross-sectional view of the rubber clip hole.

[0044] Figure 13 This is a schematic diagram of a long-channel concrete 3D printing nozzle printing system with a dual-nozzle printer assembly.

[0045] The labels in the diagram mean:

[0046] Pumping machine 1, pumping machine hopper 11, sealing rubber ring 12, vibrating rod 13, bellows 14, vibration damping spring 15, vibration damping plate 16, transmission hose 17, stirring screw 18, fixing outer ring 121, sealing inner ring 122, bolt hole 123.

[0047] Pumping pipe 2, vibration joint 21, pump pipe 22, temperature-controlled water pipe 23;

[0048] 3. Nozzle screw assembly; 31. Nozzle motor; 32. Reducer; 33. Coupling; 34. Nozzle screw; 35. Bearing;

[0049] Silo assembly 4, top plate 41, base 42, bottom plate 43, feed inlet 44, silo 45, nozzle 46;

[0050] Nozzle carrier 5;

[0051] Master disk 6;

[0052] a printhead 7;

[0053] b master disk 8;

[0054] b Printer head 9. Detailed Implementation

[0055] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0056] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0057] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0058] The following specific examples, combined with... Figures 1 to 13 This application will be described in further detail.

[0059] The present invention provides a long-channel concrete 3D printing nozzle printing system, including a multi-nozzle printer assembly, at least one pump 1 for vibrating and conveying the internal printing material to the multi-nozzle printer assembly through a pumping pipe 2 for 3D printing, and a controller.

[0060] The multi-nozzle printer assembly includes a nozzle carrier 5 mounted on a three-dimensional moving component of a concrete 3D printer, multiple mother disks 8 mounted on the side of the nozzle carrier 5, and a printing nozzle fixed on the mother disks 8 and capable of rotating around the mother disks 8.

[0061] The pump hopper 11 of the pump 1 is equipped with a vibration mechanism for liquefying the printing material inside. The vibration mechanism is located above the stirring screw 18 of the pump.

[0062] This invention liquefies the printing material by setting a vibration mechanism inside the pump 1, which not only improves pumping efficiency and reduces the risk of pipe blockage, but also avoids damage to the print head and reduction in printing accuracy caused by adding a high-power vibrator inside the print head. At the same time, the independent rotatable long-channel print head can reduce the interference of skip-layer printing on the already printed layers, realizing multi-material printing and non-horizontal extrusion.

[0063] Specifically, the vibration mechanism includes vibration damping components fixed on two opposite walls of the pump hopper 11, a vibrating rod 13 disposed between the two vibration damping components, and a transmission hose 17 disposed in one of the vibration damping components and fixed to one end of the vibrating rod 13. The other end of the transmission hose 17 passes through a locking hole on the wall of the pump hopper 11 and is connected to the vibration motor. A sealing rubber ring 12 is provided in the locking hole to seal the gap between the locking hole and the transmission hose 17 to prevent printing material from overflowing.

[0064] The vibration damping assembly is used to pre-vibrate the printing material in the pump hopper 11, causing the printing material to liquefy and compact, thereby improving pumping efficiency and reducing the risk of pipe blockage. The vibration damping assembly includes a vibration damping spring 15, a vibration damping plate 16, and a bellows 14. One end of the vibration damping spring 15 is fixed to the hopper wall of the pump hopper 11, and the other end is fixed to the vibration damping plate 16. The bellows 14 is sleeved on the outside of the vibration damping spring 15 and the vibration damping plate 16. The bellows 14 and the vibration damping spring 15 are arranged in a group, with their axes coinciding. The inner diameter of the bellows 14 is larger than the outer diameter of the vibration damping spring 15, thus sealing the vibration damping spring 15 between the hopper wall of the pump hopper 11 and the vibration damping plate 16.

[0065] The end of the vibrating rod 13 is fixed to the damping plate 16. The vibrating rod 13 is fixed inside the pump hopper 11 by the damping spring 15, so that the vibration energy is effectively applied to the printing material, reducing the absorption of vibration energy by the pump hopper 11. At the same time, installing the damping spring 15 inside the bellows 14 can also prevent the printing material from affecting the damping effect of the spring. The vibrating rod 13 is located directly above the stirring screw 18, which is the power component of the pump 1 and is located at the bottom of the pump hopper 11.

[0066] The transmission hose 17 is fixed to the vibrating rod 13, providing power to the vibrating rod 13. The other end of the transmission hose 17 passes through a retaining hole in the wall of the pump hopper 11 and is connected to the vibrating motor. To seal the gap between the transmission hose 17 and the retaining hole to prevent printing material from overflowing, a sealing rubber ring 12 is provided in the retaining hole. The sealing rubber ring 12 is deformable; when the transmission hose 17 is inserted into the sealing rubber ring 12, it can expand the sealing rubber ring 12 to achieve a sealing effect, ensuring that the printing material will not overflow from the gap during vibration.

[0067] The sealing rubber ring 12 includes an annular fixed outer ring 121 and a sealing inner ring 122 vertically disposed in the center of the fixed outer ring 121 and inserted into a locking hole. The fixed outer ring 121 and the sealing inner ring 122 are concentrically arranged, and the sealing inner ring 122 communicates with the internal and external spaces of the pump hopper 11. When installing the sealing rubber ring 12, the sealing inner ring 122 is inserted into the locking hole, and the fixed outer ring 121 is made to fit against the hopper wall of the pump hopper 11. Then, the fixed outer ring 121 is fixed to the hopper wall of the pump hopper 11 using fasteners.

[0068] In this embodiment, the inner wall of the sealing inner ring 122 has a "V"-shaped cross-section in the axial direction, and its thickness in the radial direction gradually decreases from the middle to both sides. Specifically, the thickness of the sealing rubber ring 12 is 5~20 mm, the inner diameter of the sealing inner ring 122 at the middle position is 0.8~2 mm smaller than the outer diameter of the transmission hose 17, and the inner diameter at both edges is 0.6~2 mm larger than the outer diameter of the transmission hose 17.

[0069] Preferably, the sealing rubber ring 12 is an integral injection molded structure.

[0070] Each pump is connected to a printhead via a pumping pipe 2. The pumping pipe 2 is composed of multiple pump pipe sections 22 spliced ​​together. A temperature-controlled water pipe 23 is wound around the outside of the pump pipe 22. Vibration joints 21 are provided at the ends of the pump pipes 22 that connect to the discharge port of the pump hopper 11 and at the ends of the pump pipes 22 connected to each other. The vibration joints 21 can be controlled by a controller to switch on and off and adjust the vibration frequency. The temperature-controlled water pipe 23 can be controlled by a controller to switch on and off and adjust the water temperature and water speed. By designing the pumping pipe 2 as a multi-segment pumping pipeline and installing vibration joints 21 (vibrators) at the pump pipe joints, the risk of pipe blockage during material conveying pauses and restarts can be reduced, as can the difficulty of maintaining the pump pipe after blockage.

[0071] The printhead includes a printhead screw assembly 3 and a silo assembly 4.

[0072] The nozzle screw assembly 3 includes a nozzle motor 31, a reducer 32 and a coupling 33 mounted on the nozzle motor 31, a nozzle screw 34 connected to the output end of the nozzle motor 31, and a bearing 35 disposed at the lower part of the nozzle screw 34. The bearing 35 is mounted inside the silo 45 to constrain the center of the nozzle screw 34 to the center of the silo 45. The reducer 32, coupling 33, and nozzle motor 31 jointly drive the nozzle screw 34 to rotate under the control of the controller. The bearing 35 at the lower part of the nozzle screw 34 can be completely removed from the silo assembly 4 along with the entire nozzle screw assembly 3 for easy cleaning or maintenance.

[0073] The silo assembly 4 includes a top plate 41 and a bottom plate 43 arranged in parallel, a base 42 fixed to the nozzle carrier 5 and welded to the top plate 41 and the bottom plate 43 as a single unit, a silo 45 fixed to the bottom plate 43 with its upper end extending upward to the upper surface of the top plate 41, and a nozzle 46 disposed at the lower end of the silo 45. The upper part of the silo 45 is provided with an inlet 44 for connection to the pumping pipe 2. The inlet 44 is welded to the upper part of the silo 45 near the top plate 41 and is located above the bottom plate 43. In this embodiment, the silo 45 is elongated, with a length-to-diameter ratio of 10 to 25. The distance between the lower surface of the bottom plate 43 and the upper surface of the top plate 41 does not exceed 0.4 times the length of the silo 45. The nozzle 46 at the bottom of the silo 45 is replaceable. When the nozzle screw assembly 3 is inserted downward into the silo 45, the center of the nozzle screw 34 is restricted to the center of the silo 45, and its nozzle motor 31 and reducer 32 are fixed on the top plate 41.

[0074] The concrete 3D printer is also equipped with a temperature-controlled water pipe on its three-dimensional moving component. This water pipe can spray water mist onto the printing area and its on / off state, as well as its water temperature and flow rate, can be controlled by a controller.

[0075] In this embodiment, the multi-nozzle printer assembly is a dual-nozzle printer assembly. Its nozzle carrier 5 is equipped with two sets of master discs and printing nozzles, namely a master disc 6, a printing nozzle 7, b master disc 8, and b printing nozzle 9. Both a printing nozzle 7 and b printing nozzle 9 are cylindrical in shape. The nozzle carrier 5 is a component of the three-dimensional moving assembly of the concrete 3D printer used to mount the nozzles. The a master disc 6 and b master disc 8 are symmetrically installed on both sides of the nozzle carrier 5. The a printing nozzle 7 and b printing nozzle 9 are respectively installed on the a master disc 6 and the b master disc 8. The a printing nozzle 7 can rotate clockwise or counterclockwise around the a master disc 6 under the drive of the a master disc 6. The b printing nozzle 9 can rotate clockwise or counterclockwise around the b master disc 8 under the drive of the b master disc 8.

[0076] This invention also provides a printing method for a long-channel concrete 3D printing nozzle printing system, specifically including the following steps:

[0077] S1, each printhead of the multi-head printer group is connected to a pump 1 via a pump pipe 2.

[0078] S2, respectively turn on the temperature-controlled water pipe on pump pipe 2 and the three-dimensional moving component of the concrete 3D printer.

[0079] S3, add the required amount of printing material to each pump 1 according to the printing needs, and adjust each pump 1 so that the corresponding connected print head can stably extrude the printing material.

[0080] S4, according to the set printing sequence of the printing nozzles, the controller controls one of the pumps and its connected printing nozzles to start, making the printing nozzle vertically downward and the other printing nozzles vertically upward. The printing material in the pump 1 is liquefied under the vibration of the vibration mechanism and enters the pump pipe 2 from its outlet. It passes through the pump pipe 2, the inlet 44 of the printing nozzle, the hopper 45 of the printing nozzle and the nozzle 46, and is extruded from the nozzle 46 to perform the printing work. During the printing process, the printing nozzle follows its master disc to rotate according to the set printing path to dynamically adjust the direction of the printing material extruded from the nozzle of the printing nozzle. Under the drive of the three-dimensional moving component of the concrete 3D printer, it adjusts its printing layer. When the printing layer of the printing nozzle is finished, the controller controls another pump and its connected printing nozzle to start the printing work.

[0081] S5, after all printing layers have been printed, shut off pump pipe 2 and the temperature control water pipe on the three-dimensional moving component of the concrete 3D printer.

[0082] S6, move the multi-head printer assembly out of the printing range, turn all the printheads vertically downward, squeeze out the remaining printing material in the printheads, and then clean the pump 1 and the printhead screw assembly 3 of the multi-head printer assembly.

[0083] The following uses a dual-nozzle printer assembly as an example to illustrate the printing method of the long-channel concrete 3D printing nozzle printing system of the present invention.

[0084] When printing a component with a material gradient distribution using a long-channel concrete 3D printing nozzle system with a dual-nozzle printer assembly, assuming the component is a sandwich structure of 5 layers of printing material a, 30 layers of printing material b, and 5 layers of printing material a, the printing method includes the following steps:

[0085] S1. Prepare two sets of feeding systems, pumps a and b, and prepare printing material a and printing material b according to the mixing ratio and the amount of material required for printing.

[0086] The dual-head printer assembly is adjusted to its initial state, and then pumps a and b are connected to the feed inlet of printhead 7 (a) and printhead 9 (b) respectively through pump pipe 2.

[0087] S2, respectively turn on the temperature-controlled water pipe on pump pipe 2 and the three-dimensional moving component of the concrete 3D printer.

[0088] S3, add the required amount of printing material to each pump 1 according to the printing needs, and adjust pumps a and b so that the corresponding printheads can stably extrude the printing material.

[0089] The process of debugging pumps a and b is as follows: Printing material a is added to pump a. The vibrator 13 of pump a is activated synchronously with pump 1. The printing material a liquefies under the action of the vibrator 13 and, powered by pump 1, flows along the pump pipe 2 of pump a → the feed inlet 44 of print head 7 → the silo 45 of print head 7 → the nozzle 46 of print head 7. Once the printing material a is extruded from nozzle 46 and stabilized, the screw assembly of pump a and print head 7 is closed, stopping pumping and extrusion. The same operation is performed on pump b and print head 9 until the printing material b is extruded from nozzle 46 and stabilized, at which point pumping and extrusion are stopped.

[0090] S4, under the control of the controller, the vibration joint 21 of the pump a is opened and closed after 30 seconds. The pump a and the a printing nozzle 7 are turned on. The a printing nozzle 7 rotates with the a master disk 6 according to the printing path, dynamically adjusting the extrusion direction of the nozzle 46. Driven by the three-dimensional moving component, the a printing material is extruded from the nozzle 46 according to the printing path for printing work until the first 5 layers are printed. The pump a and the a printing nozzle 7 are turned off, the three-dimensional moving component stops moving, and the a printing nozzle 7 rotates with the a master disk 6 to the vertical upward position.

[0091] Under the control of the controller, the b printing nozzle 9 rotates with the b master disk 8 to the vertically downward position. The three-dimensional moving component moves the position of the b printing nozzle 9 horizontally to the position of the a printing nozzle 7 before the printing material switching. The vibration joint 21 of the pump b is opened and closed after 30 seconds. The pump b and the b printing nozzle 9 are turned on. The b printing nozzle 9 rotates with the b master disk 8 according to the printing path. The extrusion direction of the nozzle 46 is dynamically adjusted. Driven by the three-dimensional moving component, the b printing material is extruded from the nozzle 46 according to the printing path for printing work until the 35th layer is printed. The pump b and the b printing nozzle 9 are turned off. The three-dimensional moving component stops moving. The b printing nozzle 9 rotates with the b master disk 8 to the vertically upward position.

[0092] Under the control of the controller, print head 7 rotates with mother plate 6 to a vertically downward position. The three-dimensional moving component moves print head 7 horizontally to the position of print head 9 before the material switching. The vibration joint 21 of pump a is opened and closed after 30 seconds. Pump a and print head 7 are turned on. Print head 7 rotates with mother plate 6 according to the printing path, dynamically adjusting the extrusion direction of nozzle 46. Driven by the three-dimensional moving component, printing material is extruded from nozzle 46 according to the printing path for printing until all printing layers are printed. Pump a and print head 7 are turned off, and the three-dimensional moving component stops moving.

[0093] S5, after all printing layers have been printed, shut off pump pipe 2 and the temperature control water pipe on the three-dimensional moving component of the concrete 3D printer.

[0094] S6. Move the dual-head printer assembly out of the printing range. Turn both printhead 7 (a) and printhead 9 (b) to the vertical downward position to squeeze out excess printing material. Add clean water to each of the pumps 1 to rinse until the water discharged from the printheads is basically clear. Completely remove each screw assembly and rinse until the surface is clean. After the screw assembly is dried, it is reinstalled and the dual-head unit is restored to its initial state.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A long-channel concrete 3D printing nozzle printing system, characterized in that, The system includes a multi-nozzle printer assembly, at least one pump (1) for vibrating and conveying the printing material inside the assembly through a pump pipe (2) to the multi-nozzle printer assembly for 3D printing, and a controller. The multi-nozzle printer assembly includes a nozzle carrier (5) mounted on a three-dimensional moving component of a concrete 3D printer, multiple mother discs (8) mounted on the side of the nozzle carrier (5), and printing nozzles fixed on the mother discs (8) and rotatable around the mother discs (8). The pump hopper (11) of the pump (1) is provided with a vibration mechanism for vibrating the printing material inside to liquefy the printing material. The vibration mechanism is located above the stirring screw (18) of the pump. The vibration mechanism includes vibration damping components fixed on two opposite walls of the pump hopper (11), a vibrating rod (13) disposed between the two vibration damping components, and a transmission hose (17) disposed in one of the vibration damping components and fixed to one end of the vibrating rod (13). The other end of the transmission hose (17) passes through a hole in the wall of the pump hopper (11) and is connected to the vibration motor. A sealing rubber ring (12) is provided in the hole to seal the gap between the hole and the transmission hose (17) to prevent printing material from overflowing. The vibration damping assembly includes a vibration damping spring (15), a vibration damping plate (16), and a bellows (14). One end of the vibration damping spring (15) is fixed to the wall of the pump hopper (11), and the other end is fixed to the vibration damping plate (16). The bellows (14) is sleeved on the outside of the vibration damping spring (15) and the vibration damping plate (16). The pumping pipe (2) is spliced ​​from multiple sections of pump pipe (22). A temperature-controlled water pipe (23) is wrapped around the outside of the pump pipe (22). Vibration joints (21) are provided at the end of the pump pipe (22) connected to the discharge port of the pumping machine hopper (11) and at the end of the pump pipe (22) connected to the pump pipe.

2. The long-channel concrete 3D printing nozzle printing system according to claim 1, characterized in that, The sealing rubber ring (12) includes a fixed outer ring (121) in the shape of an annulus and a sealing inner ring (122) vertically arranged in the center of the fixed outer ring (121) and inserted into a card hole. The fixed outer ring (121) is fixed to the wall of the pump hopper (11) by fasteners.

3. The long-channel concrete 3D printing nozzle printing system according to claim 2, characterized in that, The inner wall of the sealing inner ring (122) has a "V" shaped cross section in the axial direction, and its thickness in the radial direction gradually shrinks from the middle to both sides.

4. The long-channel concrete 3D printing nozzle printing system according to claim 1, characterized in that, The print head includes a print head screw assembly (3) and a silo assembly (4). The silo assembly (4) includes a top plate (41) and a bottom plate (43) arranged in parallel, a base (42) fixed on the print head carrier (5) for connecting the top plate (41) and the bottom plate (43), a silo (45) fixed on the bottom plate (43) and whose upper port extends upward to the upper end face of the top plate (41), and a nozzle (46) disposed at the lower end of the silo (45). The upper part of the silo (45) is provided with a feed port (44) for connecting to the pump pipe (2). The lower part of the print head screw assembly (3) is inserted downward into the silo (45) and its upper part is fixed on the top plate (41).

5. The long-channel concrete 3D printing nozzle printing system according to claim 4, characterized in that, The nozzle screw assembly (3) includes a nozzle motor (31), a reducer (32) and a coupling (33) mounted on the nozzle motor (31), a nozzle screw (34) connected to the output end of the nozzle motor (31), and a bearing (35) disposed at the lower part of the nozzle screw (34). The bearing (35) is mounted inside the silo (45) to restrict the center of the nozzle screw (34) to the center of the silo (45).

6. The long-channel concrete 3D printing nozzle printing system according to claim 1, characterized in that, The concrete 3D printer is equipped with a temperature-controlled water pipe on its three-dimensional moving component for spraying water mist onto the printing area.

7. A printing method for a long-channel concrete 3D printing nozzle printing system as described in any one of claims 1-6, characterized in that, Specifically, the following steps are included: S1, a pump (1) is connected to each printhead of the multi-head printer group through a pump pipe (2). S2, respectively turn on the pumping pipe (2) and the temperature control water pipe on the three-dimensional moving component of the concrete 3D printer; S3, add the required amount of printing material to each pump (1) according to the printing requirements, and adjust each pump (1) so that the corresponding connected print head can stably extrude the printing material. S4, according to the set printing sequence of the printing nozzles, the controller controls one of the pumps and its connected printing nozzles to start, and makes the printing nozzle vertically downward and the other printing nozzles vertically upward. The printing material in the pump (1) is liquefied under the vibration of the vibration mechanism and enters the pump pipe (2) from its outlet. It passes through the pump pipe (2), the inlet (44) of the printing nozzle, the hopper (45) of the printing nozzle and the nozzle (46), and is extruded from the nozzle (46) to perform printing. During the printing process, the printing nozzle follows its mother plate to rotate according to the set printing path to dynamically adjust the direction of the printing material extruded from the nozzle of the printing nozzle. Under the drive of the three-dimensional moving component of the concrete 3D printer, it adjusts its printing layer. When the printing layer of the printing nozzle is finished, the controller controls another pump and its connected printing nozzle to start printing. S5, after all printing layers have been printed, shut off the pump pipe (2) and the temperature control water pipe on the three-dimensional moving component of the concrete 3D printer; S6, move the multi-head printer assembly out of the printing range and turn all the printheads vertically downwards. After squeezing out the remaining printing material in the printheads, clean the pump (1) and the printhead screw assembly (3) of the multi-head printer assembly.

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