3D printing titanium powder mixing system and mixing method thereof

Abstract

The invention relates to a 3D printing titanium powder mixing system and a mixing method thereof. The system comprises a first feeding unit used for conveying new powder, a second feeding unit used for conveying old powder and a mixing module. And the mixing module comprises a mixing hopper and an overturning mechanism for driving the mixing hopper to overturn. During working, the system alternately conveys new powder and old powder with preset weight into the mixing hopper through the powder supply pipeline for primary mixing; then, the feeding pipe is disconnected from the powder supply pipeline, and the discharging opening is kept closed, so that the mixing hopper forms a closed container; and finally, the turnover mechanism drives the closed container to turn over to realize secondary uniform mixing. The problem that in the prior art, the cost is high due to the fact that old powder is wasted due to the fact that the old powder is difficult to mix safely and evenly is solved, efficient recycling of the old powder is achieved, the production cost of 3D printing is greatly reduced, and meanwhile it is guaranteed that the quality of mixed powder meets the high-precision printing requirement.

Description

Technical Field

[0001] This invention relates to the technical field of 3D printing powder processing, and more specifically, to a 3D printing titanium powder mixing system and mixing method thereof. Background Technology

[0002] 3D printing (additive manufacturing) technology is widely used in aerospace and high-end medical fields, but the price of titanium alloy powder raw materials is extremely expensive, resulting in high printing production costs. During the 3D printing process, a large amount of unmelted titanium powder (used powder) remains in the printing chamber. Theoretically, this powder still has the value of being reused after sieving.

[0003] However, in actual production applications of existing technologies, due to the lack of automated devices for safely and uniformly mixing new and old titanium powder, the old powder generated after the first wave of printing is often not mixed with new powder in the correct proportions for reuse in high-precision printing. Instead, this old powder is usually treated as waste, downgraded, recycled, or even discarded. This "no recycling, no mixing" situation directly leads to a huge waste of raw materials, forcing the use of brand-new titanium powder for each printing job, thus significantly increasing the manufacturing cost of 3D printing.

[0004] To address the aforementioned issues, the applicant has developed a 3D printing titanium powder mixing system and its mixing method that can automatically and uniformly mix old and new powders. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a 3D printing titanium powder mixing system and mixing method, which addresses the above-mentioned deficiencies of the prior art.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows: On one hand, the present invention provides a 3D printing titanium powder mixing system, comprising a first feeding unit for conveying new powder, a second feeding unit for conveying old powder, and a mixing module for uniformly mixing the new powder and the old powder; both the first and second feeding units include a powder feeding pipe and a power component for driving the titanium powder in the powder feeding pipe to move towards the mixing module, and a first switching valve is provided at the end of the powder feeding pipe; the mixing module includes a mixing hopper and a flipping mechanism for driving the mixing hopper to flip back and forth; the top of the mixing hopper is provided with an inlet pipe and a second switching valve for controlling the opening and closing of the inlet pipe, and the bottom is provided with an outlet pipe and a third switching valve for controlling the opening and closing of the outlet pipe; When the third switch valve is closed, the ends of the powder supply pipes of the first and second feeding units can be selectively connected to the feed pipe of the mixing hopper through the first and second switch valves to alternately supply a predetermined weight of new powder and old powder into the mixing hopper to achieve initial mixing. After feeding is completed, the first and second switching valves are closed, the feed pipe is disconnected from the end of the powder supply pipe, and the third switching valve remains closed, so that the mixing hopper forms a sealed container; after the flipping mechanism is started, it can drive the sealed mixing hopper to flip back and forth, so that the new powder and old powder in the hopper can be mixed evenly for a second time.

[0007] The 3D printing titanium powder mixing system of the present invention includes a weighing module located downstream of the power component on the powder supply pipe. The weighing module includes a weighing hopper for temporarily storing materials and a weighing sensor for detecting the weight of the materials in the weighing hopper. When the weighing sensor detects that the weight of the materials has reached a preset value, it controls the corresponding power component to stop operating and the first switching valve to close. The first switching valve is located on the powder outlet pipe at the lower end of the weighing hopper. Both the mixing hopper and the weighing hopper are also equipped with monitoring sensor components for real-time monitoring of the internal environmental parameters of the hopper to ensure explosion-proof safety.

[0008] The 3D printing titanium powder mixing system of the present invention includes a first connecting pipe slidably sleeved at the end of the powder supply pipes of the first feeding unit and the second feeding unit; the inner wall of the first connecting pipe is tightly fitted with the outer wall of the powder supply pipe, and the outer diameter of the powder supply pipe is the same as the outer diameter of the feed pipe of the mixing hopper; a first lifting component connected to the first connecting pipe is provided above the mixing hopper. When the mixing hopper is in the feeding stage, the first lifting component drives the first connecting pipe to move downward, so that the first connecting pipe is simultaneously sleeved on the end of the powder supply pipe and the feeding pipe, thereby achieving a sealed connection between the powder supply pipe and the feeding pipe through the first connecting pipe. When the mixing hopper completes feeding and enters the mixing stage, the first lifting component drives the first connecting pipe to move upward, so that it is completely separated from the feeding pipe, thereby making the powder supply pipe and the feeding pipe in a separable disconnected state.

[0009] The 3D printing titanium powder mixing system of the present invention includes a mixing pipe correspondingly provided at the lower end of the discharge pipe; a second connecting pipe slidably sleeved at the upper end of the mixing pipe; the inner wall of the second connecting pipe is tightly fitted with the outer wall of the mixing pipe, and the outer diameter of the mixing pipe is the same as the outer diameter of the discharge pipe; a second lifting assembly is provided below the mixing hopper, and the second lifting assembly is drivenly connected to the second connecting pipe. When the mixing hopper is in the discharge stage, the second lifting component drives the second connecting pipe to move upward, so that the second connecting pipe is simultaneously sleeved on the mixing pipe and the discharge pipe, thereby achieving a sealed connection between the discharge pipe and the mixing pipe through the second connecting pipe. When the mixing hopper is in the non-discharge stage, the second lifting component drives the second connecting pipe to move downward, so that it is completely separated from the discharge pipe, thereby making the discharge pipe and the mixing pipe in a separable disconnected state.

[0010] The 3D printing titanium powder mixing system of the present invention includes a sampler on the discharge pipe for extracting a sample of the mixed titanium powder.

[0011] The 3D printing titanium powder mixing system of the present invention includes a storage box module for storing the uniformly mixed titanium powder connected to the end of the mixing tube.

[0012] The 3D printing titanium powder mixing system of the present invention includes a buffer and shock-resistant mechanism inside the feed inlet of the weighing hopper; the buffer and shock-resistant mechanism includes an inverted umbrella-shaped guide shroud and a plurality of elastic damping columns connected between the top edge of the guide shroud and the inner wall of the feed inlet; the cone angle of the guide shroud is 100° to 140°, and its surface is provided with a plurality of through holes for diverting powder and balancing air pressure; the elastic damping columns are evenly distributed along the circumference of the feed inlet, and their axes form an angle of 15° to 30° with the axis of the feed inlet of the weighing hopper.

[0013] The 3D printing titanium powder mixing system of the present invention includes an ultrasonic transducer assembly installed on the outer wall of the weighing hopper; the ultrasonic transducer assembly includes an amplitude transformer and a piezoelectric ceramic transducer fixed to the end of the amplitude transformer; the top end of the amplitude transformer is fixed to the side wall of the weighing hopper, and a coupling medium layer for transmitting ultrasonic waves is provided between the contact surface of the amplitude transformer and the weighing hopper, the vibration transmission direction of which is perpendicular to the generatrix of the side wall of the weighing hopper; at least three ultrasonic transducers are provided and are arranged in layers at equal intervals along the circumference of the weighing hopper.

[0014] The 3D printing titanium powder mixing system of the present invention includes an annular electrostatic eliminator on the inner side of the powder supply pipe near the weighing hopper; the annular electrostatic eliminator includes an insulating base, a high-voltage generator embedded in the inner annular surface of the insulating base, and a plurality of discharge needles radially arranged on the inner annular surface of the insulating base; the tips of the discharge needles point to the central axis of the powder supply pipe, and the tips of the discharge needles are located at 1 / 3 to 2 / 3 of the pipe diameter from the central axis of the powder supply pipe.

[0015] On the other hand, the present invention also provides a mixing method using a 3D printing titanium powder mixing system as described in any of the preceding claims, comprising the following steps: Step S1: Close the third switch valve at the bottom of the mixing hopper and ensure that its feed pipe is in a connectable state with the powder supply pipe ends of the first and second feeding units; Step S2: Control the first feeding unit and the second feeding unit to alternately feed a predetermined weight of new powder and old powder into the mixing hopper, so that the new powder and old powder are initially mixed as they fall into the mixing hopper; Step S3: After both the new powder and the old powder have been conveyed, close the first switch valve of the first feeding unit and the second feeding unit, as well as the second switch valve of the mixing hopper, so that the mixing hopper is disconnected from the powder supply pipeline and forms a sealed container; then start the turning mechanism to drive the sealed mixing hopper to turn back and forth, so that the new powder and the old powder inside are fully and evenly mixed, and the secondary mixing is completed. Step S4: After the secondary mixing is completed, stop the turning mechanism, open the third switch valve at the bottom of the mixing hopper, and discharge the uniformly mixed titanium powder through the discharge pipe.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a system specifically designed for the automatic and uniform mixing of new and old powder. By setting up independent first and second feeding units, the feeding ratio of old powder to new powder can be precisely controlled, ensuring thorough and uniform mixing. This allows old powder, which would otherwise be considered waste, to meet the process requirements of high-precision 3D printing and be reused in production. This directly reduces the consumption of expensive new titanium powder, achieving the recycling of titanium powder resources and thus significantly reducing the manufacturing cost of 3D printing.

[0017] 2. This invention employs a unique "disconnection after feeding" design. After feeding is complete, the feed pipe disconnects from the powder supply pipe at its end, making the mixing hopper an independent, sealed container during the mixing stage. This structure completely eliminates the mechanical constraints and interference of external rigid pipes on the hopper's tumbling motion, allowing the tumbling mechanism to drive the hopper to tumble freely over large angles and multiple axes. This solves the problem of limited tumbling angles and insufficient mixing caused by pipeline constraints in existing equipment, ensuring that old and new powders can undergo intense convection, shearing, and diffusion within a sealed space, achieving highly uniform secondary mixing, guaranteeing the consistency of the physical properties of the mixed powder, and meeting the stringent powder quality requirements of high-end printing applications.

[0018] 3. After feeding is completed, this invention closes the first, second, and third switching valves and physically disconnects the pipeline connections, creating a completely sealed container in the mixing hopper. This sealed state effectively prevents the entry of external air (oxygen and moisture), preventing oxidation or dust explosions during the vigorous tumbling and mixing process. This eliminates safety hazards during the recycling of used powder, providing reliable equipment assurance for enterprises to safely utilize used powder. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. 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. Figure 1 This is a schematic diagram of the structure of a 3D printing titanium powder mixing system according to Embodiment 1 of the present invention. Figure 1 .

[0020] Figure 2 This is a schematic diagram of the structure of a 3D printing titanium powder mixing system according to Embodiment 1 of the present invention. Figure 2 .

[0021] Figure 3 yes Figure 1 A schematic diagram of the structure of the first feeding unit 10.

[0022] Figure 4 yes Figure 3 A schematic diagram of the structure of the power component 12.

[0023] Figure 5 yes Figure 3 A schematic diagram of the structure of the weighing module 40.

[0024] Figure 6 yes Figure 5 A cross-sectional view of the weighing module 40.

[0025] Figure 7 yes Figure 3 A schematic diagram of the structure of the ring-shaped static eliminator 46.

[0026] Figure 8 yes Figure 1 A schematic diagram of the structure of the mixing tank 30. Detailed Implementation

[0027] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0030] Furthermore, the terms indicating orientation, such as "up, down, front, back, left, right, upper end, lower end, longitudinal," etc., are all based on the posture and position of the device or equipment described in this solution during normal use.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 creative effort are within the protection scope of the present invention.

[0032] Example 1: An embodiment of the present invention provides a 3D printing titanium powder mixing system, such as... Figure 1-2 As shown, this system is mainly used to precisely, uniformly, and safely mix new titanium powder (unused or uncontaminated powder) with old titanium powder (recycled powder after printing) in a preset ratio to meet the high powder quality requirements of 3D printing. The system mainly includes a first feeding unit 10 for conveying new powder, a second feeding unit 20 for conveying old powder, a mixing module 30 for thoroughly and uniformly mixing the new and old titanium powders, and a weighing module 40 for accurately measuring the material weight.

[0033] The first feeding unit 10 and the second feeding unit 20 are symmetrical and independent, both used for precise conveying and metering of titanium powder. Each feeding unit includes a powder feeding pipe 11. The input end of the powder feeding pipe 11 has a U-shaped structure and its end extends vertically upward, and is equipped with a material storage hopper 01 for temporary storage of materials. The two material storage hoppers are used to store new titanium powder and old titanium powder, respectively. The upper end of the material storage hopper 01 is equipped with a receiving port that communicates with its inner cavity. Both the receiving port and the input end of the powder feeding pipe 11 are equipped with manual valves for controlling the addition and start / stop of raw materials.

[0034] like Figure 3 As shown, a power assembly 12 is installed on the powder supply pipe 11 to provide conveying power and drive the titanium powder to move along the pipe toward the mixing module 30. Furthermore, the powder supply pipe 11 includes an upper main pipe 111, a lower main pipe 112, two branch pipes 113 connecting the two, and a conveying pipe 114 connecting the outlet of the weighing module 40 and the inlet of the mixing module 30; the upper ends of both branch pipes 113 are connected to the inlet end of the upper main pipe 111; the upper main pipe 111 is inverted U-shaped, with its outlet extending downwards to the weighing hopper 41 and communicating with its interior; the powder seal formed by this inverted U-shaped structure effectively prevents the powder in the weighing hopper 41 from flowing back; the lower ends of the two branch pipes 113 converge and communicate with the outlet end of the lower main pipe 112. To precisely control the conveying process, an electromagnetic valve 114 is installed on the powder supply pipe 11 upstream of the power assembly 12, i.e., on the lower main pipe 112, to control the opening and closing of the powder flow path in that section of the pipe.

[0035] like Figure 4 As shown, the power assembly 12 may include dust boxes 121 disposed on the inner sides of the two branch pipes 113 respectively, and a motor drive mechanism 122 for driving the impeller inside the dust box 121 to rotate; the dust box 121 is vertically arranged, and its inner bottom surface is provided with a channel communicating with the branch pipe 113; the motor drive mechanism includes a drive shaft that passes through the outer wall of the branch pipe 113, and a magnetic fluid sealing device is provided between the drive shaft and the branch pipe 113, which can effectively prevent titanium powder dust from leaking out and ensure that the vacuum or inert atmosphere inside the pipeline is not destroyed, thus ensuring the absolute sealing and safety of the conveying environment.

[0036] To ensure precise addition of new and old titanium powder according to a preset ratio, a weighing module 40 is installed on the powder supply pipe 11 downstream of the power component 12 (i.e., in the powder outflow direction). For example... Figure 5As shown, the weighing module 40 includes a weighing hopper 41 for temporarily storing materials and a weighing sensor 42 for detecting the weight of the materials in the weighing hopper 41. The end of the powder supply pipe 11 extends above the weighing hopper 41, and a first switching valve 13 is provided on the powder outlet pipe located at the lower end of the weighing hopper 41 to control the feeding of materials from the weighing hopper 41 to the mixing module 30. When the weighing sensor 42 detects that the material weight has reached a preset value, it controls the corresponding power component 12 to stop operating and the first switching valve 13 to close. Both the mixing module 30 and the weighing hopper 41 are also equipped with monitoring sensor components 43 for real-time monitoring of the internal environmental parameters of the hopper to ensure explosion-proof safety.

[0037] The monitoring sensor assembly 43 includes an oxygen sensor 431 for real-time monitoring of oxygen concentration in the hopper, a temperature and humidity sensor 432 for monitoring internal temperature and humidity, and a pressure sensor 433 for monitoring the pressure difference between the inside and outside of the hopper to ensure fluidization stability. By feeding back the data collected in real time by the above sensors to the control system, the system can ensure that the hopper is always in a low-oxygen, constant-temperature and suitable micro-positive-pressure state, thereby effectively preventing safety accidents such as oxidation reaction or dust explosion of titanium powder during the mixing process.

[0038] The weighing module 40 also includes a control unit, which is electrically connected to the weighing sensor 42 and the power assembly 12. During operation, the control unit controls the power assembly 12 to run at a first speed (high speed), conveying powder to the weighing hopper 41 through the powder supply pipe 11. When the weight data received by the control unit reaches a preset percentage threshold (e.g., 90% or 95%) of the preset target weight, the control unit reduces the power assembly 12 to a second speed (low speed) for slow feeding to reduce impact. When the weight data reaches the difference between the preset target weight and the inertia compensation value, the control unit immediately stops running and closes the first switching valve 13, thereby ensuring high measurement accuracy.

[0039] To further optimize the weighing process, such as Figure 6 As shown, the weighing hopper 41 has a buffer and shock-absorbing mechanism 44 inside its feed inlet. The buffer and shock-absorbing mechanism 44 includes an inverted umbrella-shaped guide shroud 441 and several elastic damping columns 442 connecting the top edge of the guide shroud 441 to the inner wall of the feed inlet. The guide shroud 441 has a cone angle of 100° to 140°, and its surface has several through holes 443 for diverting powder and balancing air pressure. The elastic damping columns 442 are evenly distributed along the circumference of the feed inlet, and their axes form an angle of 15° to 30° with the axis of the feed inlet of the weighing hopper 41, effectively buffering the impact force of falling powder and assisting in its return to its original position.

[0040] Furthermore, to prevent powder from bridging or sticking to the wall within the weighing hopper 41, an ultrasonic transducer assembly 45 is installed on the outer wall of the weighing hopper 41. The ultrasonic transducer assembly 45 includes an amplitude transformer and a piezoelectric ceramic transducer fixed to the end of the amplitude transformer. The top of the amplitude transformer is fixed to the side wall of the weighing hopper 41, and a coupling medium layer for transmitting ultrasonic waves is provided between the contact surface of the amplitude transformer and the weighing hopper 41, with the vibration transmission direction perpendicular to the generatrix of the side wall of the weighing hopper 41. At least three ultrasonic transducer assemblies 45 are provided, and they are arranged in layers at equal intervals along the circumference of the weighing hopper 41 to ensure uniform vibration. This assembly transmits high-frequency vibration to the hopper wall through the amplitude transformer, causing the powder to be in a micro-vibration state, disrupting the powder bridging structure, and thus allowing for smooth flow. Simultaneously, the flow guide design at the inlet also contributes to the uniform dispersion of the powder, further optimizing the powder's flow properties and ensuring the continuity and accuracy of metering.

[0041] Furthermore, to eliminate static electricity buildup during powder conveying, an annular static eliminator 46 is provided on the inner side of the powder supply pipe 11 near the weighing hopper 41; as shown... Figure 7 As shown, the annular static eliminator 46 includes an insulating base 461, a high-voltage generator 462 embedded in the inner annular surface of the insulating base 461, and a plurality of discharge needles 463 arranged radially on the inner annular surface of the insulating base 461; the tips of the discharge needles 463 point towards the central axis of the powder supply pipe 11, and the tips of the discharge needles 463 are located at 1 / 3 to 2 / 3 of the pipe diameter from the central axis of the powder supply pipe 11 to ensure the best static elimination effect.

[0042] like Figure 1 and Figure 8 As shown, in this embodiment, the mixing module 30 includes a mixing hopper 31 and a flipping mechanism 32 that drives the mixing hopper 31 to rotate back and forth. The flipping mechanism 32 can be constructed using a rotary motor, a reducer, and a programmable controller, which can drive the mixing hopper 31 to rotate to achieve the best mixing effect. The mixing hopper 31 has symmetrically arranged rotating shafts at both ends, and the output end of the rotary motor is fixedly connected to either rotating shaft. A feed pipe 33 is provided at the top of the mixing hopper 31, and a second switching valve 34 is installed on the feed pipe 33 to control the feed inlet of the mixing hopper 31. A discharge pipe 35 is provided at the bottom of the mixing hopper 31, and a third switching valve 36 is installed on the discharge pipe 35 to control the discharge outlet of the mixing hopper 31.

[0043] The third switching valve 36 remains closed. At this time, the ends of the powder supply pipes 11 of the first feeding unit 10 and the second feeding unit 20 are selectively connected to the feed pipe 33 of the mixing hopper 31 via their respective first switching valves 13 and the second switching valve 34. The system alternately opens the first and second feeding units according to a preset program, sequentially feeding a predetermined weight of new powder and old powder into the mixing hopper 31. During the process of the powder falling into the mixing hopper, the natural disturbance caused by the falling point, trajectory, and accumulation achieves the initial mixing of the new and old powders.

[0044] After all powder has been added, all first switching valves 13 and second switching valves 34 of the mixing hopper are closed, cutting off the connection between the mixing hopper 31 and the external supply pipeline. Simultaneously, the third switching valve 36 at the bottom remains closed. At this point, the mixing hopper 31 becomes a completely sealed container. Subsequently, the tilting mechanism 32 is activated, driving the sealed mixing hopper 31 to repeatedly tilt and shake. Under this mechanical tilting action, the new and old titanium powders in the hopper are fully convected, sheared, and diffused, achieving deep and uniform secondary mixing, ensuring that the mixing uniformity meets process requirements.

[0045] To achieve a separable and sealed connection between the feeding unit and the mixing module, the ends of the powder supply pipes 11 of the first feeding unit 10 and the second feeding unit 20 are slidably fitted with first connecting pipes 14; the inner wall of the first connecting pipe 14 is tightly fitted with the outer wall of the powder supply pipe 11, and the outer diameter of the powder supply pipe 11 is the same as the outer diameter of the feed pipe 33 of the mixing hopper 31; a first lifting assembly 15 connected to the first connecting pipe 14 is provided above the mixing hopper 31.

[0046] When the mixing hopper 31 is in the feeding stage, the first lifting component 15 drives the first connecting pipe 14 to move downward, so that the first connecting pipe 14 is simultaneously sleeved on the end of the powder supply pipe 11 and the feeding pipe 33, thereby achieving a sealed connection between the powder supply pipe 11 and the feeding pipe 33 through the first connecting pipe 14.

[0047] When the mixing hopper 31 completes feeding and enters the mixing stage, the first lifting component 15 drives the first connecting pipe 14 to move upward, so that it is completely separated from the feeding pipe 33, thereby making the powder supply pipe 11 and the feeding pipe 33 in a separable disconnected state, which facilitates the subsequent back-and-forth shaking of the mixing hopper.

[0048] Similarly, a mixing pipe 16 is provided at the lower end of the discharge pipe 35; a second connecting pipe 17 is slidably sleeved at the upper end of the mixing pipe 16; the inner wall of the second connecting pipe 17 is tightly fitted with the outer wall of the mixing pipe 16, and the outer diameter of the mixing pipe 16 is the same as the outer diameter of the discharge pipe 35; a second lifting assembly 18 is provided below the mixing hopper 31, and the second lifting assembly 18 is drivenly connected to the second connecting pipe 17.

[0049] When the mixing hopper 31 is in the discharge stage, the second lifting component 18 drives the second connecting pipe 17 to move upward, so that the second connecting pipe 17 is simultaneously sleeved on the mixing pipe 16 and the discharge pipe 35, thereby enabling the discharge pipe 35 to achieve sealed communication with the mixing pipe 16 through the second connecting pipe 17.

[0050] When the mixing hopper 31 is in the non-discharge stage, the second lifting component 18 drives the second connecting pipe 17 to move downward, so that it is completely separated from the discharge pipe 35, thereby making the discharge pipe 35 and the mixing pipe 16 in a separable disconnected state.

[0051] The first connecting pipe 15 and the second connecting pipe 17 not only enable the upper and lower pipes to be tightly connected, but also have a limiting function for the upper and lower pipes, ensuring precise alignment.

[0052] Furthermore, the discharge pipe 35 is also equipped with a sampler 37 for extracting mixed titanium powder samples, which facilitates quality inspection and allows for the rapid extraction of representative powder samples without disrupting the overall sealed environment of the system, in order to verify the mixing uniformity and various physicochemical properties of the powder.

[0053] Furthermore, the end of the mixing pipe 16 is also connected to a storage box module 50 for storing the uniformly mixed titanium powder.

[0054] The system works as follows: 1. Feeding preparation: The first lifting component 15 is activated, which moves the first connecting pipe 14 down to connect the corresponding powder supply pipe 11 to the feed pipe 33 of the mixing hopper 31; the third switch valve 36 remains closed.

[0055] 2. Precise feeding: The system starts the first feeding unit 10 and the second feeding unit 20. According to the preset program, the speed of the power component 12 is adjusted by the control unit. The predetermined weight of new powder and old powder are precisely measured by the weighing module 40 and then fed into the mixing hopper 31. The powder is initially mixed due to natural disturbance during the falling process.

[0056] 3. Sealed Mixing: After all powder has been added, all first switching valves 13 and second switching valves 34 of the mixing hopper are closed. The first lifting assembly 15 drives the first connecting pipe 14 to move upward, cutting off the connection between the mixing hopper and the outside. At this time, the mixing hopper becomes a completely sealed container. Subsequently, the tilting mechanism 32 is activated, driving the sealed mixing hopper to repeatedly tilt and shake. The mechanical tilting action allows the new and old titanium powders to fully convect, shear, and diffuse, achieving a deep and uniform secondary mixing.

[0057] 4. Discharge and Storage: After uniform mixing, the flipping mechanism 32 resets, and the second lifting component 18 drives the second connecting pipe 17 to move upward, connecting the discharge pipe 35 and the mixing pipe 16. The third switch valve 36 is opened to discharge the mixed titanium powder into the storage box module 50. After discharge is completed, the second connecting pipe 17 moves downward and resets.

[0058] Example 2 This invention also provides a mixing method using the 3D printing titanium powder mixing system described in Example 1, comprising the following steps: Step S1: Preparation and Sealing Close the third switch valve at the bottom of the mixing hopper, and drive the first connecting pipe to disconnect from the feed pipe through the first lifting component, and at the same time drive the second connecting pipe to disconnect from the discharge pipe through the second lifting component, so as to ensure that the feed pipe of the mixing hopper and the powder supply pipe ends of the first and second feeding units are in a state of being connectable but not connected. Step S2: Initial mixing and feeding: S2.1: Control the weighing module of the first feeding unit to weigh the new powder: open the corresponding valve on its powder supply pipeline, start its power component to run at the first speed, and transport the new powder to its weighing hopper at high speed; collect weight data in real time through the weighing sensor, and when the weight data reaches the preset ratio threshold of the preset target weight, control the power component to reduce to the second speed for slow and precise feeding; when the weight data reaches the difference between the preset target weight and the inertia compensation value, control the power component to stop running and close the corresponding valve to complete the accurate weighing of the new powder; S2.2: Control the first lifting component to drive the first connecting pipe to move downward, and seal the end of the powder supply pipe of the first feeding unit to the feed pipe of the mixing hopper through the first connecting pipe; open the first switch valve of the first feeding unit and the second switch valve of the mixing hopper, and discharge the weighed new powder into the mixing hopper; S2.3: Repeat steps S2.1 and S2.2, but switch to the second feeding unit to discharge the weighed old powder into the same mixing hopper. The new powder and old powder are initially mixed as they alternately fall into the mixing hopper. S2.4: Repeat the above alternating feeding process until all the predetermined weights of new powder and old powder have been conveyed; Step S3: Sealing and Secondary Mixing: S3.1: Close the first switch valve of all feeding units and the second switch valve of the mixing hopper; control the first lifting assembly to drive the first connecting pipe to move upward, so that it is completely separated from the feeding pipe, thereby completely disconnecting the mixing hopper from all feeding pipes; S3.2: At this time, the third switch valve of the mixing hopper remains closed, and the mixing hopper constitutes a completely sealed container; S3.3: Activate the flipping mechanism to drive the sealed mixing hopper to flip back and forth at a preset speed and angle, so that the new powder and old powder inside are fully and evenly mixed in a sealed environment to complete the secondary mixing; Step S4: Material discharge: S4.1: After the secondary mixing is completed, stop the flipping mechanism; S4.2: Control the second lifting component to drive the second connecting pipe to move upward, so as to seal and connect the discharge pipe of the mixing hopper with the mixing pipe through the second connecting pipe; S4.3: Open the third switch valve at the bottom of the mixing hopper to discharge the uniformly mixed titanium powder through the discharge pipe and mixing pipe to the storage box module; S4.4: During the discharge process, the ultrasonic transducer assembly on the weighing hopper can be activated to generate high-frequency vibration to break the powder "bridging" and "hanging" phenomena, ensuring smooth discharge without residue; S4.5: After the material discharge is completed, close the third switch valve and control the second lifting assembly to drive the second connecting pipe to move downward so that it is completely separated from the discharge pipe.

[0059] Throughout the mixing and weighing process, the monitoring sensor assembly monitors the oxygen concentration, temperature, humidity, and pressure inside the mixing and weighing hoppers in real time, and the annular electrostatic eliminator continuously eliminates static electricity generated during powder conveying, ensuring that the entire process meets the explosion-proof safety requirements for flammable and explosive titanium powder.

[0060] 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 protection scope of the present invention.

Claims

1. A 3D printing titanium powder mixing system, characterized in that, The system includes a first feeding unit for conveying new powder, a second feeding unit for conveying old powder, and a mixing module for uniformly mixing the new and old powders. Both the first and second feeding units include a powder feeding pipe and a power assembly for driving the titanium powder within the powder feeding pipe toward the mixing module. A first switching valve is located at the end of the powder feeding pipe. The mixing module includes a mixing hopper and a flipping mechanism for driving the mixing hopper to rotate back and forth. The top of the mixing hopper is provided with an inlet pipe and a second switching valve for controlling the on / off state of the inlet pipe, while the bottom is provided with an outlet pipe and a third switching valve for controlling the on / off state of the outlet pipe. When the third switch valve is closed, the ends of the powder supply pipes of the first and second feeding units can be selectively connected to the feed pipe of the mixing hopper through the first and second switch valves to alternately supply a predetermined weight of new powder and old powder into the mixing hopper to achieve initial mixing. After feeding is completed, the first and second switching valves are closed, the feed pipe is disconnected from the end of the powder supply pipe, and the third switching valve remains closed, so that the mixing hopper forms a sealed container; after the flipping mechanism is started, it can drive the sealed mixing hopper to flip back and forth, so that the new powder and old powder in the hopper can be mixed evenly for a second time.

2. The 3D printing titanium powder mixing system according to claim 1, characterized in that, A weighing module is also provided on the powder supply pipeline downstream of the power unit. The weighing module includes a weighing hopper for temporarily storing materials and a weighing sensor for detecting the weight of the materials in the weighing hopper. When the weighing sensor detects that the weight of the materials has reached a preset value, it controls the corresponding power unit to stop running and the first switching valve to close. The first switching valve is located on the powder outlet pipe at the lower end of the weighing hopper. Both the mixing hopper and the weighing hopper are also equipped with monitoring sensor components for real-time monitoring of the internal environmental parameters of the hopper to ensure explosion-proof safety.

3. The 3D printing titanium powder mixing system according to claim 1 or 2, characterized in that, The first feeding unit and the second feeding unit each have a first connecting pipe slidably fitted at the end of their powder supply pipes; the inner wall of the first connecting pipe is tightly fitted with the outer wall of the powder supply pipe, and the outer diameter of the powder supply pipe is the same as the outer diameter of the feed pipe of the mixing hopper; a first lifting assembly connected to the first connecting pipe is provided above the mixing hopper. When the mixing hopper is in the feeding stage, the first lifting component drives the first connecting pipe to move downward, so that the first connecting pipe is simultaneously sleeved on the end of the powder supply pipe and the feeding pipe, thereby achieving a sealed connection between the powder supply pipe and the feeding pipe through the first connecting pipe. When the mixing hopper completes feeding and enters the mixing stage, the first lifting component drives the first connecting pipe to move upward, so that it is completely separated from the feeding pipe, thereby making the powder supply pipe and the feeding pipe in a separable disconnected state.

4. The 3D printing titanium powder mixing system according to claim 3, characterized in that, A mixing pipe is provided at the lower end of the discharge pipe; a second connecting pipe is slidably sleeved at the upper end of the mixing pipe; the inner wall of the second connecting pipe is tightly fitted with the outer wall of the mixing pipe, and the outer diameter of the mixing pipe is the same as the outer diameter of the discharge pipe; a second lifting assembly is provided below the mixing hopper, and the second lifting assembly is drivenly connected to the second connecting pipe. When the mixing hopper is in the discharge stage, the second lifting component drives the second connecting pipe to move upward, so that the second connecting pipe is simultaneously sleeved on the mixing pipe and the discharge pipe, thereby achieving a sealed connection between the discharge pipe and the mixing pipe through the second connecting pipe. When the mixing hopper is in the non-discharge stage, the second lifting component drives the second connecting pipe to move downward, so that it is completely separated from the discharge pipe, thereby making the discharge pipe and the mixing pipe in a separable disconnected state.

5. The 3D printing titanium powder mixing system according to any one of claims 1, 2, and 4, characterized in that, The discharge pipe is also equipped with a sampler for extracting mixed titanium powder samples.

6. The 3D printing titanium powder mixing system according to claim 4, characterized in that, The mixing pipe is also connected to a storage box module for storing the uniformly mixed titanium powder at its end.

7. The 3D printing titanium powder mixing system according to claim 2, characterized in that, The weighing hopper has a buffer and shock-absorbing mechanism inside its feed inlet. The buffer and shock-absorbing mechanism includes an inverted umbrella-shaped guide shroud and several elastic damping columns connected between the top edge of the guide shroud and the inner wall of the feed inlet. The guide shroud has a cone angle of 100° to 140° and its surface has several through holes for diverting powder and balancing air pressure. The elastic damping columns are evenly distributed along the circumference of the feed inlet, and their axes form an angle of 15° to 30° with the axis of the feed inlet of the weighing hopper.

8. The 3D printing titanium powder mixing system according to claim 7, characterized in that, An ultrasonic transducer assembly is installed on the outer wall of the weighing hopper; the ultrasonic transducer assembly includes an amplitude transformer and a piezoelectric ceramic transducer fixed to the end of the amplitude transformer; the top of the amplitude transformer is fixed to the side wall of the weighing hopper, and a coupling medium layer for transmitting ultrasonic waves is provided between the contact surface of the amplitude transformer and the weighing hopper, the vibration transmission direction of which is perpendicular to the generatrix of the side wall of the weighing hopper; at least three ultrasonic transducer assemblies are provided, and they are arranged in layers at equal intervals along the circumference of the weighing hopper.

9. The 3D printing titanium powder mixing system according to any one of claims 2, 7 and 8, characterized in that, An annular electrostatic eliminator is provided on the inner side of the end of the powder supply pipe near the weighing hopper; the annular electrostatic eliminator includes an insulating base, a high-voltage generator embedded in the inner annular surface of the insulating base, and a plurality of discharge needles arranged radially on the inner annular surface of the insulating base; the tip of the discharge needle points to the central axis of the powder supply pipe, and the tip of the discharge needle is located at 1 / 3 to 2 / 3 of the pipe diameter from the central axis of the powder supply pipe.

10. A mixing method, using the 3D printing titanium powder mixing system as described in any one of claims 1-9, characterized in that, Includes the following steps: Step S1: Close the third switch valve at the bottom of the mixing hopper and ensure that its feed pipe is in a connectable state with the powder supply pipe ends of the first and second feeding units; Step S2: Control the first feeding unit and the second feeding unit to alternately feed a predetermined weight of new powder and old powder into the mixing hopper, so that the new powder and old powder are initially mixed as they fall into the mixing hopper; Step S3: After both the new powder and the old powder have been conveyed, close the first switch valve of the first feeding unit and the second feeding unit, as well as the second switch valve of the mixing hopper, so that the mixing hopper is disconnected from the powder supply pipeline and forms a sealed container; then start the turning mechanism to drive the sealed mixing hopper to turn back and forth, so that the new powder and the old powder inside are fully and evenly mixed, and the secondary mixing is completed. Step S4: After the secondary mixing is completed, stop the turning mechanism, open the third switch valve at the bottom of the mixing hopper, and discharge the uniformly mixed titanium powder through the discharge pipe.

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