Extrusion mechanism of concrete 3D printer

Abstract

The invention belongs to the technical field of building material production, and discloses a concrete 3D printer extrusion mechanism, a printing extrusion structure of the mechanism can be connected with a mechanical arm or a multi-axis printing platform, the internal structure of a printing head is complex and high in collaboration, during printing, concrete enters an extrusion flow guide channel through a pumping-in pipeline, a motor drives a spiral belt rod to convey the concrete, and the printing head is connected with the mechanical arm or the multi-axis printing platform. The mortar flow wheel is driven to rotate, the first wheel push rod is pushed to move leftwards, air in the spray pipe is compressed, enters the inflation pipe through the one-way air channel and then enters the mortar falling spray pipe, mortar is pushed by air to fill building material lamination gaps, meanwhile, a mortar piston is pushed, continuous supply of repairing mortar is ensured, the material surface roughness is effectively improved, the cost is reduced, and the construction period is shortened. And the slurry flow wheel pushes the second wheel push rod to move rightwards, an auxiliary in the liquid pressing pipe is extruded to enter the extrusion flow guide channel, the concrete performance is enhanced, the auxiliary can be supplemented during resetting, the printing quality is improved, defects are reduced, the material quality and the use performance are optimized, and the defects of traditional concrete 3D printing are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of building material production, in particular to a concrete 3D printer extrusion mechanism. Background Art

[0002] The technical background of concrete 3D printers stems from the deep integration of additive manufacturing (3D printing) and the construction industry. Its development relies on the coordinated progress of materials science, automated control, computer modeling and robotics. Traditional construction techniques are limited by template dependence, high labor costs and low efficiency in the construction of complex structures. Concrete 3D printing can directly form materials without molds by stacking materials layer by layer, greatly improving design freedom and construction efficiency. Its core challenges include developing concrete materials that meet fluidity, extrudability and rapid curing characteristics (such as optimizing rheological properties through additives), as well as path planning and real-time calibration technology for high-precision motion control systems (such as robotic arms or multi-axis printing platforms). In addition, combined with BIM (Building Information Modeling) and AI algorithms, digital design and dynamic construction optimization of complex structures can be achieved. This technology is regarded as a key direction for promoting the low-carbon and intelligent transformation of the construction industry, and has shown potential in the construction of low-cost housing, special-shaped building components and emergency facilities.

[0003] At present, when concrete 3D printers are in actual operation, the surface of the building materials printed and produced presents a unique layered structure. The roughness of this layered exterior wall is relatively high, which seriously affects the appearance and subsequent performance of the building materials. In order to make the surface of the building materials smoother and meet the standards and aesthetic requirements of construction, most manufacturers have to use manual polishing or other supporting equipment to process the wall flatness. This additional process not only significantly increases the production cost, including labor cost, equipment purchase and operation cost, but also greatly increases the labor intensity of workers and prolongs the construction period, which to a certain extent offsets the original potential advantages of 3D printing technology in cost and efficiency.

[0004] To this end, a concrete 3D printer extrusion mechanism is proposed. Summary of the invention

[0005] The object of the present invention is to provide a concrete 3D printer extrusion mechanism to solve the problem of high surface roughness of building materials produced by concrete 3D printers mentioned in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a concrete 3D printer extrusion mechanism, comprising:

[0007] A printing extrusion structure having components connected to a robotic arm or a multi-axis printing platform and connected to the robotic arm or the multi-axis printing platform by bolts;

[0008] The printing extrusion structure includes a printing head, wherein a pumping pipeline and an auxiliary agent pipeline are respectively provided at the middle and upper position inside the printing head corresponding to the inner and outer surfaces of the printing building material, and two wheel chambers which are interconnected with the extrusion flow guide are symmetrically provided inside the printing head, and a slurry flow wheel is rotatably provided inside the wheel chamber, and a first wheel push rod and a second wheel push rod are respectively slidably interspersed inside the wheel chamber of the printing head, and the piston ends of the first wheel push rod and the second wheel push rod respectively extend out of the printing head to the inside of the nozzle and the pressure liquid pipe, and the nozzle and the pressure liquid pipe are integrally connected at the middle and lower position of the left and right sides of the printing head;

[0009] Among them, a gas pressure spring is fixed on the left end wall inside the nozzle, and the right end of the gas pressure spring is fixed to the piston end of the first wheel push rod, a one-way air passage is opened inside the first wheel push rod, and an air intake valve for discharging air into the one-way air passage is installed at the air intake end of the one-way air passage, an air pumping pipe is integrally connected to the lower side of the nozzle and the print head connection end, the lower end of the air pumping pipe is integrally connected to the pulp drop nozzle, and a valve for discharging air into the pulp drop nozzle is installed at the connecting port with the pulp drop nozzle. The deflated jet air valve, the upper end of the slurry nozzle is sealed and connected to the output end of the valve tube by bolts, the right end of the valve tube is connected to the left end of the nozzle by bolts, the internal sliding and sealing connection of the valve tube is connected to a mortar piston, the right side of the interior of the mortar piston is penetrated to the right by an L-shaped slurry flow valve channel of a specified length, the mortar piston is integrally connected with several push connecting rods on the surrounding side of the slurry flow valve channel output port, and the right ends of the push connecting rods extend and penetrate into the interior of the nozzle and are fixed to the piston end of the first round of push rods.

[0010] Preferably, the interior of the print head is equipped with a motor, and the shaft of the motor is connected to the upper end of the screw rod through a coupling to drive the screw rod to rotate. The screw rod is rotatably arranged inside the extrusion guide channel opened at the lower part of the print head through a bearing seat and a bearing frame.

[0011] Preferably, one end of the pumping pipeline is connected to the concrete supply equipment through a matching pipeline, a one-way valve is arranged inside the auxiliary agent pipeline, and the end that passes through to the outside is provided with an interface for connecting the pipeline.

[0012] Preferably, the wheel chamber is located on the same side as the pumping pipeline and the auxiliary agent pipeline, and a front eaves plate for blocking the influx of concrete is integrally provided on the upper side of the wheel chamber and the connecting port of the extrusion guide channel.

[0013] Preferably, the pulp flow wheel is a multi-impeller structure, and the impeller blades are arranged in a curved claw bucket shape.

[0014] Preferably, the ends of the first wheel push rod and the second wheel push rod inserted into the wheel chamber are both provided with hemispherical ball ends, and the ball ends of the first wheel push rod and the second wheel push rod can be in sliding contact with the arc surface of the pulp flow wheel.

[0015] Preferably, the slurry spraying pipe is arranged in an L shape, the lower part of the pipe body is tilted upward along a specified angle, and the diameter of the lower part of the pipe body gradually decreases from left to right and from far away from the building material to close to the building material, and a slurry spraying nozzle is arranged at the end close to the building material.

[0016] Preferably, the valve tube is a three-way tube structure with four ends, wherein the left and right pipelines located on the lower side are the input and output pipelines of the mortar respectively, and the left end is open. The lower end of the slurry flow valve channel downwardly passes through the liquid inlet one-way valve, and when the mortar piston moves to the left, the lower end of the slurry flow valve channel can communicate with the input pipeline on the left side of the valve tube.

[0017] Preferably, a hydraulic spring is fixed to the right end wall inside the liquid pressure tube, and the left end of the hydraulic spring is fixed to the piston end of the second wheel push rod, and the side surface of the liquid pressure tube is respectively installed with a liquid outlet check valve and a liquid inlet check valve for one-way output and one-way input of the auxiliary agent on the upper and lower sides near the right end, wherein the liquid inlet check valve and the pipeline are connected to the auxiliary agent supply equipment, and the liquid outlet check valve and the pipeline are connected to the interface of the auxiliary agent pipeline.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention sets up a printing extrusion structure. During printing, concrete enters the extrusion guide channel from the pump inlet pipeline, and the motor drives the screw rod to rotate, driving the concrete to move downward, prompting the slurry flow wheel to rotate. The slurry flow wheel pushes the first round push rod to move left, and the first round push rod compresses the air pressure spring and the air in the nozzle at the same time. When the air pressure reaches the opening pressure of the air inlet valve, the air enters the space on the right side of the nozzle through the one-way airway, and then enters the pumping pipe for storage. As the first round push rod continues to move left, the gas in the pumping pipe increases, and the pressure reaches the pressure relief opening condition of the jet valve. , gas enters the slurry nozzle, and the gas pushes the mortar in it. The mortar is sprayed from the nozzle at the lower end of the slurry nozzle under pressure on the gaps between the building materials, filling the gaps, improving the surface stacking structure, reducing roughness, improving the appearance quality, reducing subsequent processing procedures, reducing costs, and shortening the construction period. At the same time, the left movement of the first round of push rods also pushes the mortar piston to the left, so that the slurry flow valve channel is connected with the input pipeline on the left side of the valve pipe. At this time, the repair mortar pumped by the mortar supply equipment enters the slurry nozzle through the valve pipe and the slurry flow valve channel for storage, ensuring the continuity and stability of the repair work;

[0020] 2. The present invention sets a printing extrusion structure. During the printing process, the slurry flow wheel rotates to push the second wheel push rod to move right. The second wheel push rod compresses the hydraulic spring and squeezes the auxiliary material in the pressure liquid tube. The auxiliary material enters the auxiliary pipeline through the liquid outlet one-way valve. As the second wheel push rod continues to move right, more auxiliary material enters the auxiliary pipeline. When the opening pressure of the one-way valve in the auxiliary pipeline is reached, the auxiliary material enters the extrusion guide channel and is mixed with the concrete under the action of the screw rod. This dynamic input method enables the auxiliary agent to be added to the concrete in real time and accurately, thereby enhancing the fluidity, extrudability and rapid curing characteristics of the concrete, improving the printing performance, reducing printing defects, and improving the quality and performance of building materials. At the same time, during the resetting process of the second wheel push rod, the auxiliary material will be sucked and supplemented according to the negative pressure condition to ensure the continuity of the supply of auxiliary material, so that the performance of the concrete is always good during the printing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the overall structural view of the present invention;

[0022] Figure 2 It is an overall cross-sectional view of the present invention;

[0023] Figure 3 For the present invention Figure 2 Enlarged view of point A in the middle;

[0024] Figure 4 For the present invention Figure 2 Enlarged view of point B in the middle;

[0025] Figure 5 It is a schematic diagram of the first wheel push rod, mortar piston and their connection structure of the present invention;

[0026] Figure 6 This is a cross-sectional view of the first wheel push rod, mortar piston and their connection structure of the present invention.

[0027] In the figure:

[0028] 1. Print extrusion structure;

[0029] 11. Print head; 111. Extrusion guide channel; 1111. Front eaves plate; 112. Screw rod; 113. Pumping pipeline; 114. Auxiliary agent pipeline;

[0030] 12. Pulp flow wheel;

[0031] 13. Nozzle; 131. First round push rod; 1311. One-way airway; 1312. Air intake valve; 132. Air pump; 1321. Air jet valve; 133. Air pressure spring; 134. Mortar piston; 1341. Slurry flow valve; 1342. Push rod; 135. Valve pipe; 136. Slurry drop nozzle;

[0032] 14. Liquid pressure pipe; 141. Second wheel push rod; 142. Hydraulic spring; 143. Liquid inlet check valve; 144. Liquid outlet check valve. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figures 1 to 6 , the present invention provides a technical solution of a concrete 3D printer extrusion mechanism:

[0035] A concrete 3D printer extrusion mechanism, comprising:

[0036] A printing extrusion structure 1, which has a component connected to a robotic arm or a multi-axis printing platform, and is connected to the robotic arm or the multi-axis printing platform by bolts;

[0037] The printing extrusion structure 1 comprises a printing head 11,

[0038] The interior of the print head 11 is equipped with a motor, and the shaft of the motor is connected to the upper end of the screw rod 112 through a coupling to drive the screw rod 112 to rotate. The screw rod 112 is rotatably arranged in the extrusion guide channel 111 opened at the lower part of the interior of the print head 11 through a bearing seat and a bearing frame. The interior of the print head 11 is provided with a pumping pipeline 113 and an auxiliary agent pipeline 114 at a position in the middle and upper part of the extrusion guide channel 111 corresponding to the inner and outer sides of the printed building material, respectively, wherein one end of the pumping pipeline 113 is connected to the concrete supply equipment through a matching pipeline, and the auxiliary agent pipeline 114 is provided with a one-way valve inside the pipeline, and the end that passes through to the outside is provided with an interface for connecting the pipeline, and the interior of the print head 11 is symmetrically provided with two wheel chambers that are interconnected with the extrusion guide channel 111 on both sides of the extrusion guide channel 111 near the extrusion port, and the wheel chamber is on the same side as the pumping pipeline 113 and the auxiliary agent pipeline 114, and the wheel chamber is connected to the extrusion guide channel. A front eaves plate 1111 is integrally provided on the upper side of the connecting port 111 to block the influx of concrete. A slurry wheel 12 is rotatably provided inside the wheel chamber of the print head 11. The slurry wheel 12 is a multi-impeller structure, and the impeller blade is set in a curved claw bucket shape. The first wheel push rod 131 and the second wheel push rod 141 are respectively slidably interspersed in the wheel chamber of the left and right print heads 11, and the ends of the first wheel push rod 131 and the second wheel push rod 141 inserted into the wheel chamber are both set in a hemispherical shape, and the ball ends of the first wheel push rod 131 and the second wheel push rod 141 can slide in contact with the arc surface of the slurry wheel 12, and the piston ends of the first wheel push rod 131 and the second wheel push rod 141 extend out of the print head 11 to the inside of the nozzle 13 and the pressure liquid pipe 14 respectively, and can slide along the pipe wall of the nozzle 13 and the pressure liquid pipe 14 under the premise of sealing, and the nozzle 13 and the pressure liquid pipe 14 are integrally connected at the middle and lower positions on the left and right sides of the print head 11;

[0039] The side of the nozzle 13 is provided with a one-way air inlet valve near the left end, a gas spring 133 is fixed on the left end wall inside the nozzle 13, and the right end of the gas spring 133 is fixed to the piston end of the first wheel push rod 131, so as to limit the sliding and move the first wheel push rod 131. The first wheel push rod 131 is provided with a T-shaped one-way air passage 1311 of a specified length from the piston end along the axis to the other end, and the air inlet end of the one-way air passage 1311 is provided with a gas spring 133 installed inside the one-way air passage 1311. The nozzle 13 is connected to the print head 11 at the lower side of the connection end thereof and is provided with an air pumping pipe 132, the air pumping pipe 132 is arranged in an L-shape, and the lower end thereof is connected to the slurry drop nozzle 136, and an air jet valve 1321 for releasing air into the slurry drop nozzle 136 is installed at the communication port with the slurry drop nozzle 136, the slurry drop nozzle 136 is arranged in an L-shape, the lower part of the tube body thereof is tilted upward at a specified angle, and the lower part of the tube body is arranged from left to right, from far away from the building material to close to the building material The diameter of the pipe for the material gradually decreases, and a nozzle for pressurized spraying is arranged at one end close to the building material. The upper end of the slurry nozzle 136 is sealed and connected to the output end of the valve pipe 135 by bolts. The valve pipe 135 is a three-way pipe structure with four ends. Among them, the left and right pipelines located on the lower side are the input and output pipelines of the mortar respectively. The left end is open, and the right end is connected to the left end of the nozzle 13 by bolts. The inside of the valve pipe 135 is slidingly and sealably connected to the mortar piston 134. The right side of the inside of the mortar piston 134 is open to the right. An L-shaped slurry flow valve channel 1341 of a specified length is provided, and the lower end of the slurry flow valve channel 1341 downwardly penetrates the liquid inlet one-way valve 143, and when the mortar piston 134 moves to the left, the lower end of the slurry flow valve channel 1341 can communicate with the input pipeline on the left side of the valve tube 135, and the mortar piston 134 is integrally connected with a plurality of push rods 1342 on the surrounding side of the output port of the slurry flow valve channel 1341, and the right ends of the push rods 1342 extend and penetrate into the interior of the nozzle 13 and are fixed to the piston end of the first round push rod 131.

[0040] During the printing process, the concrete supply device connected to the pumping pipe 113 will pump the concrete into the extrusion guide channel 111, and then the motor inside the print head 11 will rotate and drive the screw rod 112 to make the screw rod 112 spirally transport the concrete downward. The downwardly moving concrete will drive the slurry flow wheel 12 to rotate during the movement. The rotating slurry flow wheel 12 will push the first wheel push rod 131 and the second wheel push rod 141 to move left and right respectively according to the arc surface. Among them, the left-moving first wheel push rod 13 1 will compress the gas spring 133 and compress the air drawn into the nozzle 13. During the compression process, the compressed air reaches the opening pressure of the air inlet valve 1312. Then, the compressed air passes through the air inlet valve 1312 and enters the inside of the one-way air passage 1311, and enters the right side space of the nozzle 13 along the one-way air passage 1311. The compressed air entering the right side of the nozzle 13 will enter the inside of the pumping pipe 132 along the nozzle 13 and be stored in the pumping pipe 132. As the push rod 131 continues to move left, the gas entering the air pumping pipe 132 will continue to increase and reach the pressure relief opening condition of the air jet valve 1321. Then, the air will pass through the air jet valve 1321 and enter the interior of the slurry nozzle 136, and push the existing mortar in the slurry nozzle 136, so that the mortar moves downward along the slurry nozzle 136, and is pressurized and sprayed between the printed building material layers by the nozzle at the lower end, thereby filling the gaps between the printed building material layers. The first round push rod 131 that moves to the left will cooperate with the push connecting rod 1342 to synchronously push the mortar piston 134 to the left, and then the mortar piston 134 that moves to the left will gradually align and connect the input port of the slurry flow valve channel 1341 with the input pipeline of the valve pipe 135. After the slurry flow valve channel 1341 is connected with the valve pipe 135, the mortar supply equipment will pump the repair mortar into the interior of the valve pipe 135, and it will pass through the slurry flow valve channel 1341 and fall into and be stored in the slurry drop nozzle 136 along the output pipeline of the valve pipe 135.

[0041] In summary, through the setting of the printing extrusion structure 1, during printing, concrete enters the extrusion guide channel 111 from the pumping pipe 113, and the motor drives the screw rod 112 to rotate, driving the concrete to move downward, prompting the slurry wheel 12 to rotate, and the slurry wheel 12 pushes the first wheel push rod 131 to move left, and the first wheel push rod 131 compresses the air pressure spring 133, and at the same time compresses the air in the nozzle 13. When the air pressure reaches the opening pressure of the air inlet valve 1312, the air enters the right side space of the nozzle 13 through the one-way air channel 1311, and then enters the pumping pipe 132 for storage. As the first wheel push rod 131 continues to move left, the gas in the pumping pipe 132 increases, and the pressure reaches the injection valve 13 When the pressure relief opening condition is 21, gas enters the slurry nozzle 136, and the gas pushes the mortar therein. The mortar is sprayed under pressure from the nozzle at the lower end of the slurry nozzle 136 on the gaps between the stacked layers of building materials to fill the gaps, improve the surface stacking structure, reduce roughness, improve the appearance quality, reduce subsequent processing steps, reduce costs, and shorten the construction period. At the same time, the left movement of the first round of push rod 131 also pushes the mortar piston 134 to the left, so that the slurry flow valve channel 1341 is connected to the left input pipeline of the valve pipe 135. At this time, the repair mortar pumped by the mortar supply equipment enters the slurry nozzle 136 for storage through the valve pipe 135 and the slurry flow valve channel 1341, thereby ensuring the continuity and stability of the repair work.

[0042] As an embodiment of the present invention, Figure 2 and Figure 4 As shown, a hydraulic spring 142 is fixed to the right end wall inside the pressure liquid tube 14, and the left end of the hydraulic spring 142 is fixed to the piston end of the second wheel push rod 141, and the side of the pressure liquid tube 14 is respectively installed with a liquid outlet check valve 144 and a liquid inlet check valve 143 for one-way output and one-way input of the auxiliary agent on the upper and lower sides near the right end, wherein the liquid inlet check valve 143 is connected to the auxiliary agent supply equipment through a matching pipeline, and the liquid outlet check valve 144 is connected to the interface of the auxiliary agent pipeline 114 through a matching pipeline.

[0043] During the printing process, the concrete supply device connected to the pumping pipeline 113 will pump the concrete into the extrusion guide channel 111, and then the motor inside the print head 11 will rotate and drive the screw rod 112 to make the screw rod 112 spirally transport the concrete downward. The downwardly moving concrete will drive the slurry flow wheel 12 to rotate during the movement. The rotating slurry flow wheel 12 will push the first wheel push rod 131 and the second wheel push rod 141 to move left and right respectively according to the arc surface. Among them, the rightward movement of the second wheel push rod 141 will squeeze the liquid pressure pipe 14 while compressing the hydraulic spring 142. The auxiliary material drawn into the interior enters the interior of the auxiliary agent pipeline 114 through the liquid outlet one-way valve 144, and as the second wheel push rod 141 continues to move, more auxiliary material will enter the interior of the auxiliary agent pipeline 114, and then reach the opening pressure of the one-way valve inside the auxiliary agent pipeline 114, and enter the interior of the extrusion guide channel 111 through the one-way valve. The auxiliary material entering the extrusion guide channel 111 will be mixed into the interior of the concrete and mixed with the concrete under the action of the screw rod 112, thereby enhancing the fluidity, extrudability and rapid curing characteristics of the concrete material.

[0044] To sum up, through the setting of the printing extrusion structure 1, during the printing process, the pulp flow wheel 12 rotates to push the second wheel push rod 141 to move right, and the second wheel push rod 141 compresses the hydraulic spring 142 to squeeze the auxiliary material in the pressure tube 14, and the auxiliary material enters the auxiliary pipeline 114 through the liquid outlet one-way valve 144. As the second wheel push rod 141 continues to move right, more auxiliary materials enter the auxiliary pipeline 114. When the opening pressure of the one-way valve in the auxiliary pipeline 114 is reached, the auxiliary material enters the extrusion guide channel 111 and is mixed with the concrete under the action of the screw rod 112. This dynamic input method enables the auxiliary agent to be added to the concrete in real time and accurately, enhances the fluidity, extrudability and rapid curing characteristics of the concrete, improves the printing performance, reduces printing defects, and improves the quality and performance of building materials. At the same time, during the resetting process of the second wheel push rod 141, the auxiliary material will be sucked and supplemented according to the negative pressure condition to ensure the continuity of the supply of auxiliary materials, so that the concrete performance is always good during the printing process.

[0045] Working principle: When working, firstly, the printing extrusion structure 1 is connected to the robot arm or multi-axis printing platform by bolts, and then the path planning and real-time calibration technology of the high-precision motion control system is combined with BIM and AI algorithms to control the print head 11 to perform the 3D printing operation of concrete on the building material substrate (the above process is the existing technology in the field and is common knowledge of those skilled in the art);During the printing process, the concrete supply equipment connected to the pumping pipeline 113 will pump the concrete into the extrusion guide channel 111, and then the motor inside the print head 11 will rotate and drive the screw rod 112, so that the screw rod 112 spirally transports the concrete downward. The downward moving concrete will drive the slurry flow wheel 12 to rotate during the movement. The rotating slurry flow wheel 12 will push the first wheel push rod 131 and the second wheel push rod 141 to move left and right respectively according to the arc surface. Among them, the rightward movement of the second wheel push rod 141 will compress the hydraulic spring 142 while squeezing the auxiliary material drawn into the pressure liquid pipe 14, and the auxiliary material will enter the auxiliary agent pipeline 114 through the pipeline through the liquid outlet one-way valve 144. As the second push rod 141 continues to move, more auxiliary materials will enter the auxiliary agent pipeline 114, and then reach the opening pressure of the one-way valve inside the auxiliary agent pipeline 114, and enter the extrusion guide channel 111 through the one-way valve. The auxiliary materials entering the extrusion guide channel 111 will be mixed into the concrete and mixed with the concrete under the action of the spiral rod 112, thereby enhancing the fluidity, extrudability and rapid curing characteristics of the concrete material. In addition, the first push rod 131 that moves to the left will compress the gas spring 133 while compressing the air drawn into the nozzle 13, and during the compression process, the compressed air reaches the air inlet valve 1312 opens, and then the compressed air passes through the air inlet valve 1312 and enters the one-way air passage 1311, and enters the right side space of the nozzle 13 along the one-way air passage 1311. The compressed air entering the right side of the nozzle 13 will enter the inside of the pumping pipe 132 along the nozzle 13, and be stored inside the pumping pipe 132. As the first round of push rod 131 continues to move left, the gas entering the pumping pipe 132 will continue to increase, and reach the pressure relief opening condition of the jet valve 1321. Then the air will pass through the jet valve 1321 and enter the inside of the slurry nozzle 136, and push the existing mortar inside the slurry nozzle 136, so that the mortar moves along the slurry nozzle The tube 136 moves downward, and the nozzle at the lower end sprays the mortar between the printed building material layers under pressure to fill the gaps between the printed building material layers. At the same time, the first push rod 131 that moves to the left will cooperate with the push connecting rod 1342 to synchronously push the mortar piston 134 to move to the left, and then the mortar piston 134 that moves to the left will gradually align and connect the input port of the slurry flow valve channel 1341 with the input pipeline of the valve tube 135. After the slurry flow valve channel 1341 is connected with the valve tube 135, the mortar supply device pumps the repair mortar into the interior of the valve tube 135, and the mortar passes through the slurry flow valve channel 1341 and falls into the output pipeline of the valve tube 135 and is stored in the slurry drop nozzle 136;Then, after the blades of the pulp wheel 12 pass through the first wheel push rod 131 and the second wheel push rod 141, the pushing state of the first wheel push rod 131 and the second wheel push rod 141 will be released. At this time, the gas pressure spring 133 and the hydraulic spring 142 compressed by the first wheel push rod 131 and the second wheel push rod 141 will push the first wheel push rod 131 and the second wheel push rod 141 to quickly reset. Among them, the first wheel push rod 131 during the reset process will move right along the wall of the nozzle 13. At this time, the air space on the left side of the nozzle 13 will increase. Due to the increase in the left side space inside the nozzle 13 and the lack of air replenishment, a negative pressure environment will be generated in the space on the left side of the nozzle 13, and the negative pressure will increase with the increase in the left side space inside the nozzle 13. As the first push rod 131 moves rightward gradually, it forces the one-way air valve port at the left end of the nozzle 13 to open and replenish air into the nozzle 13. At the same time, under the traction of the first push rod 131, the mortar piston 134 will move rightward synchronously, and then the slurry flow valve channel 1341 will be staggered with the input pipeline of the valve pipe 135, and the mortar will stop supplying to the slurry drop nozzle 136. During the reset process, the second push rod 141 will also suck and replenish the auxiliary material according to the negative pressure condition; the above process will continue to be executed during the printing operation, and the spraying and repairing speed and the auxiliary material input speed will be automatically adjusted according to the concrete flow speed until the concrete building material is printed. ;

[0046] It should be noted that the nozzle of the slurry drop nozzle 136 is located between the lower layer of concrete being printed by the printing head 11 and the one that has been printed, and the nozzle direction points to the opposite direction of the printing direction of the printing head 11.

[0047] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A concrete 3D printer extrusion mechanism, comprising: A printing extrusion structure (1) having a component connected to a robotic arm or a multi-axis printing platform and connected to the robotic arm or the multi-axis printing platform by bolts; The printing extrusion structure (1) comprises a printing head (11), characterized in that: A pumping pipeline (113) and an auxiliary agent pipeline (114) are respectively provided at the middle upper position inside the printing head (11) corresponding to the inner and outer surfaces of the printing building material. Two wheel chambers that are interconnected with the extrusion guide channel (111) are symmetrically provided inside the printing head (11), and a slurry flow wheel (12) is rotatably arranged inside the wheel chamber. A first wheel push rod (131) and a second wheel push rod (141) are respectively slidably inserted inside the wheel chamber of the printing head (11). The piston ends of the first wheel push rod (131) and the second wheel push rod (141) extend out of the printing head (11) to the inside of the nozzle (13) and the pressure liquid pipe (14). The nozzle (13) and the pressure liquid pipe (14) are both integrally connected at the middle lower position of the left and right sides of the printing head (11); A gas pressure spring (133) is fixed on the left end wall inside the nozzle (13), and the right end of the gas pressure spring (133) is fixed to the piston end of the first wheel push rod (131), a one-way air passage (1311) is opened inside the first wheel push rod (131), and an air intake valve (1312) for releasing air into the one-way air passage (1311) is installed at the air intake end of the one-way air passage (1311), an air pumping pipe (132) is integrally connected to the lower side of the connection end of the nozzle (13) and the print head (11), the lower end of the air pumping pipe (132) is integrally connected to the pulp drop nozzle (136), and a valve for releasing air into the pulp drop nozzle (136) is installed at the communication port with the pulp drop nozzle (136). The upper end of the slurry nozzle (136) is sealed and connected to the output end of the valve tube (135) by bolts, and the right end of the valve tube (135) is connected to the left end of the nozzle (13) by bolts. The inside of the valve tube (135) is slidably and sealedly connected to a mortar piston (134). The right side of the inside of the mortar piston (134) is provided with an L-shaped slurry flow valve channel (1341) of a specified length. The mortar piston (134) is integrally connected to a plurality of push rods (1342) on the peripheral side of the output port of the slurry flow valve channel (1341), and the right ends of the push rods (1342) extend into the inside of the nozzle (13) and are fixed to the piston end of the first round push rod (131).

2. A concrete 3D printer extrusion mechanism according to claim 1, characterized in that: The print head (11) is equipped with a motor inside, and the motor shaft is connected to the upper end of the screw rod (112) through a coupling to drive the screw rod (112) to rotate. The screw rod (112) is rotatably arranged inside the extrusion guide channel (111) opened at the bottom of the print head (11) through a bearing seat and a bearing frame.

3. A concrete 3D printer extrusion mechanism according to claim 1, characterized in that: One end of the pumping pipeline (113) is connected to the concrete supply equipment through a matching pipeline, and a one-way valve is arranged inside the auxiliary agent pipeline (114), and one end that is connected to the outside is provided with an interface for connecting the pipeline.

4. A concrete 3D printer extrusion mechanism according to claim 1, characterized in that: The wheel chamber is located on the same side as the pumping pipeline (113) and the auxiliary agent pipeline (114), and a front eaves plate (1111) for blocking the inflow of concrete is integrally provided on the upper side of the communication port between the wheel chamber and the extrusion flow guide channel (111).

5. The concrete 3D printer extrusion mechanism according to claim 1, characterized in that: The pulp flow wheel (12) is a multi-impeller structure, and the impeller blades are arranged in a curved claw bucket shape.

6. A concrete 3D printer extrusion mechanism according to claim 1, characterized in that: One end of the first wheel push rod (131) and the second wheel push rod (141) inserted into the wheel chamber is provided with a hemispherical ball end, and the ball ends of the first wheel push rod (131) and the second wheel push rod (141) can be in sliding contact with the arc surface of the pulp flow wheel (12).

7. A concrete 3D printer extrusion mechanism according to claim 1, characterized in that: The slurry spraying pipe (136) is arranged in an L shape, the lower part of which is tilted upward at a specified angle, and the diameter of the lower part of which gradually decreases from left to right and from far away from the building material to close to the building material, and a slurry spraying nozzle is arranged at the end close to the building material.

8. The concrete 3D printer extrusion mechanism according to claim 1, characterized in that: The valve tube (135) is a three-way tube structure with four ends, wherein the left and right pipelines located on the lower side are the input and output pipelines of the mortar respectively, and the left end is open. The lower end of the slurry flow valve channel (1341) passes downward through the liquid inlet one-way valve (143), and when the mortar piston (134) moves to the left, the lower end of the slurry flow valve channel (1341) can communicate with the input pipeline on the left side of the valve tube (135).

9. A concrete 3D printer extrusion mechanism according to claim 1, characterized in that: A hydraulic spring (142) is fixed to the right end wall inside the pressure liquid pipe (14), and the left end of the hydraulic spring (142) is fixed to the piston end of the second wheel push rod (141). The side surface of the pressure liquid pipe (14) is respectively installed with a liquid outlet check valve (144) and a liquid inlet check valve (143) for one-way output and one-way input of the auxiliary agent on the upper and lower sides near the right end, wherein the liquid inlet check valve (143) is connected to the auxiliary agent supply device through a pipeline, and the liquid outlet check valve (144) is connected to the interface of the auxiliary agent pipeline (114) through a pipeline.

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