Molten droplet transition device based on electromagnetic drive hydraulic regulation and method
The electromagnetically driven, hydraulically regulated droplet transfer device solves the problems of imprecise droplet transfer, complex equipment, and uneven mixing of multiple materials in the existing technology. It achieves controllable droplet transfer and uniform mixing of multiple materials, and simplifies the equipment structure.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHANGHAI SECOND POLYTECHNIC UNIVERSITY
- Filing Date
- 2025-09-22
- Publication Date
- 2026-05-21
AI Technical Summary
Existing metal droplet jetting devices suffer from problems such as difficulty in achieving precise droplet transition, complex equipment structure, difficulty in feeding multiple materials, and uneven material mixing.
The electromagnetically driven, hydraulically regulated droplet transfer device forms an acceleration channel, a reflux channel, and regulates the flow rate of the reflux channel within the crucible shell through an excitation coil and adjustment components. Combined with laser wire feeding, it achieves uniform mixing and controllable transfer of molten metal.
It improves the controllability of molten droplets, simplifies the equipment structure, facilitates the uniform mixing and feeding of various materials, and enables flexible switching between single droplet injection and liquid flow transition.
Smart Images
Figure CN2025122831_21052026_PF_FP_ABST
Abstract
Description
A droplet transfer device and method based on electromagnetically driven hydraulic regulation Technical Field
[0001] This invention belongs to the field of metal droplet transfer technology, specifically relating to a droplet transfer device and method based on electromagnetic drive and hydraulic regulation. Background Technology
[0002] With the rapid development of high technology and advanced weaponry, the future of 3D printing is trending towards micro-nano metal refinement, multi-material composite lightweighting, and integrated design and fabrication. Uniform metal droplet jetting technology, developed in recent years, differs from other melt-based additive manufacturing technologies. It relies on pressure pulses or external disturbances to control uniform, tiny micron-sized metal droplets. Because the jetting material, droplet size, and droplet position are controllable, it facilitates the rapid printing of complex microstructures and heterogeneous materials.
[0003] In the prior art, the metal droplet ejection device and method for ejecting high-melting-point metal droplets using the same device, as disclosed in application publication number CN102672193 A, utilizes the focusing effect of a "T"-shaped rod energy focuser to concentrate stress wave energy onto the free liquid surface at the nozzle outlet below the crucible and the inert gas via a piezoelectric actuator to generate microdroplets. The microdroplet ejection process involves a stress wave generated by an impact rod striking the "T"-shaped rod, controlling the size of the metal droplets. However, the metal droplet ejection device disclosed in this application has the following problems in the metal droplet ejection process: 1. Using inert gas to promote droplet transition makes it difficult to achieve fine droplet transition and jet transition; 2. The piezoelectric actuator requires a cooling system, resulting in a bulky equipment structure; 3. The complex sealing structure makes it difficult to achieve simultaneous continuous feeding of multiple materials; 4. The mixing scheme for the dry pot structure wires cannot achieve uniform mixing and distribution of multiple materials, thus making it difficult to achieve additive manufacturing of composite materials. Technical issues
[0004] In view of the above-mentioned problems in the prior art, the technical problem to be solved by the present invention is to provide a droplet transfer device and method based on electromagnetic drive hydraulic regulation to improve the controllability of droplets. Technical solutions
[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0006] A droplet transfer device based on electromagnetic drive and hydraulic regulation includes a crucible shell for containing molten metal, a functional block disposed inside the crucible shell, and an excitation coil disposed outside the crucible shell. The bottom of the crucible shell is provided with a dropper. The functional block is connected to the inner wall of the crucible shell through multiple connecting posts. An acceleration channel is formed between the side wall of the functional block and the inner side wall of the crucible shell. The magnetic field excited by the excitation coil covers the acceleration channel. A second channel is formed between the bottom wall of the functional block and the inner bottom wall of the crucible shell. A vertically penetrating reflux channel is provided on the functional block at a position corresponding to the dropper. An adjustment component for adjusting the flow rate of the reflux channel is provided on the crucible shell.
[0007] Preferably, a fluid counter-flow bevel is provided on the bottom wall of the crucible shell at a position corresponding to the drip nozzle.
[0008] Preferably, the upper end of the reflux channel forms a flared opening, and the adjustment component includes a driving member disposed outside the crucible shell, a driving rod connected to the driving member, and a sealing block connected to the driving rod and corresponding to the shape of the flared opening. An adjustment channel is formed between the side wall of the sealing block and the flared opening. When the driving member drives the sealing block to move up and down, it changes the cross-sectional area of the adjustment channel.
[0009] Preferably, the crucible shell is provided with a wire feeding hole for feeding the wire into the crucible shell, a laser is provided outside the crucible shell for aligning with the wire inside the crucible shell, and a laser hole is provided on the crucible shell for the laser emitted by the laser to pass through.
[0010] Preferably, the laser strikes the filament with its own light, and the laser beam that penetrates the filament is then directed into the molten metal within the acceleration channel.
[0011] Preferably, the acceleration channel is in the shape of a trumpet with its opening facing downwards.
[0012] Preferably, a heat insulation block is provided between the excitation coil and the crucible shell.
[0013] Preferably, the inner wall of the dropper is provided with a superhydrophobic coating.
[0014] The present invention also provides a droplet transfer method using the above-mentioned droplet transfer device based on electromagnetic drive and hydraulic regulation, comprising the following steps:
[0015] Step 1: Place the device in a vacuum environment and determine whether the molten metal solution inside the crucible shell covers the sealing block. If it does not cover the block, feed the wire and melt the wire using a laser. The magnetic field generated by the excitation coil drives the molten metal inside the crucible shell to rotate.
[0016] Step 2: When the molten metal covers the sealing block and the metal is completely melted, the driving component moves the sealing block to the top of the stroke, and the fuse stops.
[0017] Step 3: The magnetic field generated by the excitation coil causes the molten metal solution to rotate in the acceleration channel. Its centrifugal force causes the solution to accelerate along the channel and finally collide at the fluid counter-flow bevel. The sealing block is moved downward or the voltage and frequency of the excitation coil are adjusted to regulate the pressure at the fluid counter-flow bevel. The solution flows out from the nozzle, forming a molten droplet transition.
[0018] Step 4: Continue feeding wire when the molten metal solution inside the crucible shell is below the sealing block.
[0019] Preferably, the droplet transition in step 3 includes both single-droplet injection and liquid flow transition;
[0020] The single-drop injection is achieved by adjusting the sealing block to quickly move it down to the bottom, and the solution is ejected from the nozzle under the action of water hammer effect.
[0021] The fluid flow transition is achieved by adjusting the voltage and frequency of the excitation coil and keeping the sealing block in a certain position so that the pressure at the counter-flush bevel continuously forces the solution out of the nozzle, thus achieving continuous fluid flow transition. Beneficial effects
[0022] Compared with the prior art, the present invention has the following advantages:
[0023] The present invention comprises a crucible shell, a functional block, and an excitation coil. An acceleration channel, a second channel, and a return channel are formed within the crucible shell. The flow rate of the return channel is adjusted by setting an adjustment component. A hydraulic pressure difference is formed above the nozzle by adjusting the magnitude and frequency of the excitation coil current. The molten metal is directly transferred by the change of the hydraulic pressure difference, thereby improving controllability.
[0024] The crucible shell is equipped with a wire feeding hole and a laser for heating, which reduces the complexity of the equipment and facilitates the feeding and melting of multiple and various types of wires;
[0025] The excitation coil, in conjunction with the acceleration channel, uses a magnetic field to thoroughly stir the solution, facilitating the uniform mixing of various materials.
[0026] A flared opening is provided at the upper end of the reflux channel. The adjustment component includes a blocking block corresponding to the shape of the flared opening. The flow rate of the reflux channel is adjusted by moving the blocking block up and down. The adjustment of the blocking block position, together with the adjustment of the excitation coil voltage and frequency, can form two droplet transfer modes: single droplet injection and liquid flow transfer. Attached Figure Description
[0027] Figure 1 is a schematic diagram of the device structure according to an embodiment of the present invention;
[0028] Figure 2 is a schematic diagram of the structure at the return channel in the embodiment;
[0029] Figure 3 is a circuit diagram of the excitation coil in the embodiment;
[0030] Figure 4 is a schematic diagram of the driving component structure of the embodiment. The best embodiment of the present invention
[0031] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.
[0032] As shown in Figure 1, a droplet transfer device based on electromagnetic drive and hydraulic regulation includes a crucible shell 1, a functional block 2, and an excitation coil 3. The crucible shell 1 is generally shaped like a downwardly expanding frustum-cone, and is hollow inside to contain molten metal solution. A dropper 11 is located at the center of the bottom of the crucible shell 1, and the internal space of the crucible shell 1 is connected to the outside through the dropper 11. The molten metal solution inside the crucible shell 1 is discharged through the dropper 11. In use, the entire device is located in a vacuum environment, and the outlet of the dropper 11 is located outside the vacuum environment. The inner wall of the dropper 11 is coated with a superhydrophobic coating. The dropper 11 is detachably connected to the crucible shell 1 and can be replaced. A fluid counter-flow bevel 12 is provided on the inner bottom wall of the crucible shell 1 at a position corresponding to the dropper 11. The fluid counter-flow bevel 12 is inverted conical, and its lower end is connected to the dropper 11. The upper end is connected, and the functional block 2 is set inside the crucible shell 1. The bottom of the functional block 2 is connected to the inner bottom wall of the crucible shell 1 through multiple connecting pillars 21. The functional block 2 is truncated cone-shaped. The side wall of the functional block 2 is parallel to the inner wall of the crucible shell 1. An acceleration channel 41 is formed between the outer side wall of the functional block 2 and the inner side wall of the crucible shell 1. The acceleration channel 41 is shaped like a downward-facing trumpet. A second channel 42 is formed between the bottom wall of the functional block 2 and the inner bottom wall of the crucible shell 1. The second channel 42 is a planar channel. The lower end of the second channel 42 is connected to the acceleration channel 41. A return channel 43 is provided on the functional block 2 at the position corresponding to the nozzle 11. The return channel 43 is located in the middle of the functional block 2 and runs through the functional block 2 from top to bottom. The lower end of the return channel 43 is located directly above the fluid counter-flow bevel 12. The molten metal solution in the second channel 42 can return to the top of the functional block 2 through the return channel 43.
[0033] As shown in Figures 1 and 3, the excitation coil 3 is mounted on the outer wall of the crucible shell 1. A heat insulation block is provided between the excitation coil 3 and the crucible shell 1 to insulate the heat of the crucible shell 1 and protect the excitation coil 3. The excitation coil 3 is connected to a three-phase AC power supply. The number of excitation coils 3 is a multiple of three. For example, in this embodiment, six excitation coils 3 are provided using the existing excitation coil connection method, divided into three phases: a, b, and c. Each phase forms a closed loop. The two coils of each phase are connected in series, and the angle between the projections of the two coils of each phase on the horizontal plane is 180°, thus the two coils of each phase are symmetrically arranged. The coils, placed on the outer wall of the crucible shell 1, have a 60° angle between their projections on the horizontal plane. When the excitation coil 3 is connected to an external power source, it generates a magnetic field. This magnetic field covers the acceleration channel 41, causing the molten metal solution to rotate within it. The centrifugal force accelerates the solution along the channel. The accelerated molten metal solution then moves from the periphery towards the center of the second channel 42. This molten metal solution moving towards the center of the second channel 42 is counteracted at the fluid counter-flow bevel 12. Part of it continues upward along the return channel 43, while the other part descends to the nozzle 11. The rotation of the molten metal solution under the influence of the magnetic field thoroughly mixes the different wire solutions, resulting in a uniform mixture.
[0034] As shown in Figures 1 and 2, an adjustment assembly is provided on the crucible shell 1. The adjustment assembly is used to adjust the flow rate of the reflux channel 43. The upper end face of the functional block 2 has a groove in the middle, thus forming a flared mouth 431 at the upper end of the reflux channel 43. The flared mouth 431 gradually expands from bottom to top. The adjustment assembly includes a driving component 51, a driving rod 52, and a sealing block 53. The driving component 51 is set on the outer top wall of the crucible shell 1. The driving rod 52 penetrates downward through the top of the crucible shell 1. The sealing block 53 is located inside the crucible shell 1 and is connected to the lower end of the driving rod 52. In this embodiment, the driving component 51 includes a driving bracket 511, a linear motor 512, a working rod 513, a working slider 514, a working slide rail 515, a working roller 516, and a working spring 517. The driving bracket 511 is connected to the outer top wall of the crucible shell 1. The linear motor 512 is set on the driving bracket 511. The working rod 513 is connected to the linear motor 512. When the linear motor 512 is working, it drives the working rod 513 to move left and right. 514 is connected to one end of the working rod 513. The working slide rail 515 corresponds to the working slider 514 and is connected to the drive bracket 511. When the working rod 513 moves left and right, it drives the working slider 514 to slide left and right on the working slide rail 515. The working slider 514 is a triangular block. The working roller 516 is rotatably connected to the top of the drive rod 52 and its position corresponds to the position of the working slider 514. When the working slider 514 moves to the right, the ramp part of the working slider 514 gradually moves to the right, thereby pressing the working roller 516. Since the left and right displacement of the drive rod 52 is restricted, the working roller 516 can only drive the drive rod 52 to move downward after being pressured. The working spring 517 is sleeved on the outer ring of the drive rod 52. The drive rod 52 is provided with a retaining ring corresponding to the working spring 517. When the drive rod 52 moves downward, it overcomes the elastic force of the working spring 517. When the working roller 516 is no longer under force, the drive rod 52 moves upward and returns to the initial position under the action of the elastic force of the working spring 517. The driving component 51 can also be an existing hydraulic cylinder or a servo electric slide to drive the driving rod 52 to move up and down. A heat insulation plate 15 is also provided on the outer top wall of the crucible shell 1 to reduce heat transfer. The driving rod 52 penetrates the top of the crucible shell 1 and enters the crucible shell 1. The sealing block 53 is connected to the lower end of the driving rod 52. The sealing block 53 corresponds to the shape of the flared mouth 431. The sealing block 53 is in the shape of an inverted frustum. An adjustment channel 432 is formed between the side wall of the sealing block 53 and the flared mouth 431. The adjustment channel 432 is annular. When the driving component 51 is working, it drives the sealing block 53 to move up and down through the driving rod 52. When the sealing block 53 moves up and down, it changes the cross-sectional area of the adjustment channel 432. When the sealing block 53 moves down to the lower limit of the stroke, the sealing block 53 blocks the return channel 43, and no solution flows back upward. When the sealing block 53 moves up to the upper limit of the stroke, the cross-sectional area of the adjustment channel 432 is the largest, and the flow rate of the return channel 43 is the largest.
[0035] As shown in Figure 1, a wire feeding hole 13 is provided on the side wall of the crucible shell 1. One or more wire feeding holes 13 can be provided; multiple holes allow for simultaneous feeding of multiple materials, facilitating the manufacturing of composite materials. Wire (which can be aluminum alloy, copper alloy, titanium alloy, or other metals that can be melted by lasers and generate electromagnetic induction) can be fed into the crucible shell 1 through the wire feeding hole 13. A laser 6 is provided outside the crucible shell 1, and the laser 6 is fixed to the side of the crucible shell 1 by an external bracket. The laser head of the laser 6 is located above the crucible shell 1 (when in use, the laser...). (Both the laser head and the crucible shell 1 are located in a vacuum environment). The laser 6 uses an existing laser to emit a high-energy-density laser. The crucible shell 1 has a laser hole 14 for the laser emitted by the laser 6 to pass through. After passing through the laser hole 14, the laser emitted by the laser 6 acts on the wire inside the crucible shell 1, melting the wire. The laser beam is located in the plane of the acceleration channel 41. The laser beam that penetrates the wire enters the molten metal in the acceleration channel 41, thus continuing to heat the molten metal in the acceleration channel 41 until the metal is completely melted and forms a solution. Multiple lasers 6 can be set up to act on the wire from multiple angles and continue to heat the molten metal in the acceleration channel 41. The lasers from multiple angles eventually enter the acceleration channel 41 to continue heating the molten metal.
[0036] This embodiment also provides a droplet transfer method using the above-mentioned droplet transfer device based on electromagnetic drive and hydraulic regulation, including the following steps:
[0037] Step 1: Place the device in a vacuum environment, with the outlet of the nozzle 11 located outside the vacuum environment. Determine whether the molten metal solution inside the crucible shell 1 covers the sealing block 53. If it is not covered, feed the wire and melt the wire through the laser 6. The magnetic field generated by the excitation coil 3 drives the molten metal inside the crucible shell 1 to rotate. After the wires of various materials are fed, the molten metal solution is mixed evenly under the action of the magnetic field.
[0038] Step 2: Use a temperature measuring instrument (e.g., a thermal imager) to confirm the distribution range of the metal inside the crucible shell 1. When the molten metal solution covers the sealing block 53 and the metal is completely melted, the driving component 51 moves the sealing block 53 to the upper limit of the stroke, and the fuse stops.
[0039] Step 3: The magnetic field generated by the excitation coil 3 causes the molten metal solution to rotate in the acceleration channel 41. Its centrifugal force causes the solution to accelerate along the acceleration channel 41. The accelerated solution moves from the periphery of the second channel 42 to the center of the second channel 42. The molten metal solution moving towards the center of the second channel 42 is flushed at the fluid flushing bevel 12. The sealing block 53 moves downward or the voltage and frequency of the power supply of the excitation coil 3 are adjusted to adjust the pressure at the fluid flushing bevel 12. The molten metal solution flows out from the nozzle 11, forming a droplet transition. The diameter of the droplets sprayed from the nozzle 11 is less than 3 mm.
[0040] Droplet transfer includes two types: single droplet injection and liquid flow transfer;
[0041] Single-drop injection is achieved by adjusting the sealing block 53 to quickly move it down to the bottom, and the solution is ejected from the nozzle 11 under the action of water hammer effect. Alternatively, single-drop injection can be achieved by a sudden change in the voltage or frequency of the power supply of the excitation coil 3, which causes the circulating current to accelerate suddenly, and the pressure at the upper part of the nozzle 11 changes. The solution is ejected from the nozzle 11 under the action of the changing pressure.
[0042] The fluid flow transition is achieved by adjusting and maintaining the voltage and frequency of the excitation coil 3, while keeping the sealing block 53 in a certain position so that the pressure at the counter-flush bevel 12 continuously forces the solution out of the nozzle 11, thus achieving continuous fluid flow transition.
[0043] Step 4: Continue feeding wire when the molten metal solution inside the crucible shell 1 is lower than the sealing block 53.
[0044] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A droplet transfer device based on electromagnetic actuation of hydraulic regulation, characterized in that, The device includes a crucible shell (1) for containing molten metal, a functional block (2) disposed inside the crucible shell (1), and an excitation coil (3) disposed outside the crucible shell (1). The bottom of the crucible shell (1) is provided with a nozzle (11). The functional block (2) is connected to the inner wall of the crucible shell (1) through multiple connecting posts (21). An acceleration channel (41) is formed between the side wall of the functional block (2) and the inner side wall of the crucible shell (1). The magnetic field excited by the excitation coil (3) covers the acceleration channel (41). A second channel (42) is formed between the bottom wall of the functional block (2) and the inner bottom wall of the crucible shell (1). A return channel (43) is provided on the functional block (2) at a position corresponding to the nozzle (11). An adjustment component is provided on the crucible shell (1) for adjusting the flow rate of the return channel (43).
2. The electromagnetic drive hydraulic regulated droplet transition device of claim 1, wherein, The inner bottom wall of the crucible shell (1) is provided with a fluid counter-flow bevel (12) corresponding to the drip nozzle (11).
3. The electromagnetic drive hydraulic regulated droplet transition device of claim 2, wherein, The upper end of the reflux channel (43) forms a flared mouth (431). The adjustment assembly includes a drive member (51) disposed outside the crucible shell (1), a drive rod (52) connected to the drive member (51), and a sealing block (53) connected to the drive rod (52) and corresponding to the shape of the flared mouth (431). An adjustment channel (432) is formed between the side wall of the sealing block (53) and the flared mouth (431). When the drive member (51) drives the sealing block (53) to move up and down, it changes the cross-sectional area of the adjustment channel (432).
4. The electromagnetic drive hydraulic regulated droplet transition device of claim 3, wherein, The crucible shell (1) is provided with a wire feeding hole (13) for feeding wire into the crucible shell (1), and a laser (6) is provided outside the crucible shell (1) for aligning with the wire inside the crucible shell (1). The crucible shell (1) is provided with a laser hole (14) for the laser emitted by the laser (6) to pass through.
5. The electromagnetic drive hydraulic regulated droplet transition device of claim 4, wherein, The laser (6) strikes the filament with a laser beam, and the laser beam that penetrates the filament is then injected into the molten metal in the acceleration channel (41).
6. The electromagnetic drive hydraulic regulated droplet transition device of claim 4, wherein, The acceleration channel (41) is shaped like a trumpet with its opening facing downwards.
7. The electromagnetic drive hydraulic regulated droplet transition device of claim 4, wherein, A heat insulation block is provided between the excitation coil (3) and the crucible shell (1).
8. The electromagnetic drive hydraulic regulated droplet transition device of claim 4, wherein, The inner wall of the dropper (11) is provided with a superhydrophobic coating.
9. A method of droplet transfer using a droplet transfer device based on electromagnetic drive hydraulic regulation according to any one of claims 3-8, characterized in that, Includes the following steps: Step 1: Place the device in a vacuum environment and determine whether the molten metal solution inside the crucible shell (1) covers the sealing block (53). If it is not covered, feed the wire and melt the wire through the laser (6). The magnetic field generated by the excitation coil (3) drives the molten metal inside the crucible shell (1) to rotate. Step 2: When the molten metal covers the sealing block (53) and the metal is completely melted, the driving component (51) moves the sealing block (53) to the top of the stroke, and the fuse stops. Step 3: The magnetic field generated by the excitation coil (3) causes the molten metal solution to rotate in the acceleration channel (41). Its centrifugal force causes the solution to accelerate along the channel and finally collide at the fluid counter-clamping bevel (12). The sealing block (53) is moved downward or the voltage and frequency of the excitation coil (3) are adjusted to regulate the pressure at the fluid counter-clamping bevel (12). The solution flows out from the nozzle (11) to form a molten droplet transition. Step 4: Continue feeding wire when the molten metal solution inside the crucible shell (1) is lower than the sealing block (53).
10. The droplet transfer method of claim 9, wherein, Step 3 includes two types of droplet transfer: single droplet injection and liquid flow transfer. The single-drop injection is achieved by adjusting the sealing block (53) so that the sealing block (53) moves rapidly downward to the bottom, and the solution is ejected from the nozzle (11) under the action of water hammer effect. The fluid flow transition is achieved by adjusting the voltage and frequency of the excitation coil (3) and keeping the sealing block (53) in a certain position so that the pressure at the counter-flush bevel (12) continuously forces the solution out from the nozzle (11), thus realizing continuous fluid flow transition.