Molten drop transition device and method based on electromagnetic drive hydraulic adjustment

Abstract

The invention discloses a molten drop transition device and method based on electromagnetic drive hydraulic adjustment, and belongs to the technical field of metal molten drop transition.The device comprises a crucible shell, a functional block and an excitation coil, a drip nozzle is arranged at the bottom of the crucible shell, the functional block is connected with the inner wall of the crucible shell, and an acceleration channel is formed between the side wall of the functional block and the inner wall of the crucible shell; a 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 backflow channel is formed in the functional block, and an adjusting assembly is arranged on the crucible shell. The adjusting assembly is arranged to adjust the flow of the backflow channel, the hydraulic pressure difference is formed above the drip nozzle by adjusting the current magnitude and frequency of the magnet exciting coil, molten metal is directly transited through the change of the hydraulic pressure difference, and controllability is improved; the complexity of the equipment is reduced, and feeding and melting of a plurality of or various wires are facilitated; various materials can be uniformly mixed; and two molten drop transition modes of single drop spraying and liquid flow transition can be formed.

Description

Technical Field

[0001] The invention belongs to the technical field of metal molten droplet transfer, and in particular relates to a molten droplet transfer device and method based on electromagnetic drive and hydraulic regulation. Background Art

[0002] With the rapid development of high-tech and advanced weapons and equipment, the future development of 3D printing is the trend of micro-nano metal refinement, multi-material composite lightweight and integrated design and production. Uniform metal droplet injection technology is a recent development that is different from other additive manufacturing technologies based on melting. It is based on pressure pulses or external disturbances. By controlling uniform and fine micron-sized metal droplets, the injection material, droplet size and droplet position are controllable, which facilitates the rapid printing of complex microstructures and non-uniform materials.

[0003] In the prior art, there is a metal droplet ejection device and a method for ejecting high-melting-point metal droplets using the device, which is published as CN102672193 A. The technical solution uses the focusing effect of the "T"-bar energy focuser to concentrate the stress wave energy on the free liquid surface at the nozzle outlet below the crucible and the inert gas through the piezoelectric brake to generate droplets. The droplet ejection process is caused by the impact rod impacting the "T"-bar to generate stress waves and control the size of the metal droplets. The metal droplet ejection device disclosed in the application has the following problems in the metal droplet ejection process: 1. The droplet transition is promoted by delivering inert gas, and the droplet transition is difficult to achieve fine droplet transition and jet transition; 2. The piezoelectric actuator requires a cooling system, resulting in a large equipment structure; 3. The sealing structure is complex, and it is difficult to achieve simultaneous continuous feeding of multiple materials; 4. The mixing scheme of the dry pot structure wire cannot achieve uniform mixing and distribution of multiple materials, so it is difficult to achieve additive manufacturing of composite materials. Summary of the invention

[0004] In view of the above problems existing in the prior art, the technical problem to be solved by the present invention is to provide a molten droplet transition device and method based on electromagnetic driven hydraulic regulation to improve the controllability of the molten droplet.

[0005] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A molten droplet transition device based on electromagnetic drive and hydraulic adjustment comprises a crucible shell for accommodating molten metal, a functional block arranged in the crucible shell and an excitation coil arranged outside the crucible shell, a drip nozzle is arranged at the bottom of the crucible shell, the functional block is connected to the inner wall of the crucible shell through a plurality of connecting columns, an acceleration channel is formed between the side wall of the functional block and the inner 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 reflux channel which runs through from top to bottom is arranged at a position on the functional block corresponding to the drip nozzle, and an adjustment component for adjusting the flow of the reflux channel is arranged on the crucible shell.

[0007] Preferably, a fluid counter-cut groove is provided on the inner bottom wall of the crucible shell at a position corresponding to the drip nozzle.

[0008] Preferably, a bell-mouth is formed at the upper end of the reflux channel, and the adjustment assembly includes a driving member arranged 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 bell-mouth, an adjustment channel is formed between the side wall of the sealing block and the bell-mouth, and the driving member changes the cross-sectional area of ​​the adjustment channel when driving the sealing block to move up and down.

[0009] Preferably, the crucible shell is provided with a wire feeding hole for feeding wire into the crucible shell, the crucible shell is provided with a laser aimed at the wire in the crucible shell, and the crucible shell is provided with a laser hole for laser emitted by the laser to pass through.

[0010] Preferably, the laser strikes the wire, and the laser that penetrates the wire is shot into the molten metal in the acceleration channel.

[0011] Preferably, the acceleration channel is in the shape of a trumpet with the mouth facing downward.

[0012] Preferably, a heat insulation block is provided between the excitation coil and the crucible shell.

[0013] Preferably, the inner wall of the drip nozzle is provided with a super-hydrophobic coating.

[0014] The present invention also provides a droplet transfer method, using the above droplet transfer device based on electromagnetic drive and hydraulic adjustment, comprising the following steps:

[0015] Step 1: Place the device in a vacuum environment to determine whether the molten metal solution in the crucible shell covers the blocking block. If not, feed the wire and fuse it through the laser. The magnetic field generated by the excitation coil drives the molten metal in the crucible shell to rotate.

[0016] Step 2: When the molten metal covers the blocking block and the metal is completely melted, the driving member drives the blocking block to move to the top of the stroke, and the fuse is suspended;

[0017] Step 3: The magnetic field generated by the excitation coil causes the molten metal solution to rotate in the acceleration channel. The centrifugal force thereof causes the solution to accelerate along the channel, and finally the solution is collided at the fluid counter-collision groove. The blocking block is moved downward or the voltage and frequency of the excitation coil are adjusted to adjust the pressure at the fluid counter-collision groove. The solution flows out from the drip nozzle to form a molten droplet transition.

[0018] Step 4: When the molten metal solution in the crucible shell is lower than the blocking block, continue feeding the wire.

[0019] Preferably, the droplet transfer in step 3 includes two types: single droplet injection and liquid flow transfer;

[0020] The single-drop injection is achieved by adjusting the blocking block so that the blocking block quickly moves downward to the bottom, and the solution is ejected from the drip nozzle under the action of the water hammer effect, thereby achieving single-drop injection;

[0021] The liquid flow transition is achieved by adjusting the voltage and frequency of the excitation coil and keeping the blocking block at a certain position so that the pressure at the hedging groove continuously presses the solution out of the drip nozzle, thereby achieving continuous liquid flow transition.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention is provided with a crucible shell, a functional block and an excitation coil, and an acceleration channel, a second channel and a reflux channel are formed in the crucible shell. The flow of the reflux channel is adjusted by providing an adjustment component, and a hydraulic pressure difference is formed above the drip nozzle by adjusting the current size and frequency of the excitation coil. The molten metal is directly transferred by the change of the hydraulic pressure difference, thereby improving the controllability;

[0024] 2. A wire feeding hole is set on the crucible shell, and a laser heating is set, which reduces the complexity of the equipment and facilitates the feeding and melting of multiple and various wires;

[0025] 3. The excitation coil cooperates with the acceleration channel, and the magnetic field fully stirs the solution, making it easy to mix multiple materials evenly;

[0026] 4. A bell mouth is set at the upper end of the reflux channel, and the regulating component includes a blocking block corresponding to the shape of the bell mouth. The blocking block is moved up and down to adjust the flow of the reflux channel. The adjustment of the blocking block position is coordinated with the adjustment of the excitation coil voltage and frequency, which can form two droplet transition modes: single droplet injection and liquid flow transition. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the device according to an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of the structure of the reflux channel of an embodiment;

[0029] Figure 3 is a circuit diagram of an excitation coil of an embodiment;

[0030] Figure 4 Schematic diagram of the driving structure of the embodiment. DETAILED DESCRIPTION

[0031] The present invention is further illustrated below in conjunction with specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0032] like Figure 1 As shown, a molten droplet transition device based on electromagnetic driven hydraulic regulation comprises a crucible shell 1, a functional block 2 and an excitation coil 3. The crucible shell 1 is in the shape of a truncated cone that expands downward as a whole. The crucible shell 1 is hollow and is used to contain molten metal solution. A drip nozzle 11 is provided in the middle of the bottom of the crucible shell 1. The space inside the crucible shell 1 is connected to the outside through the drip nozzle 11. The molten metal solution in the crucible shell 1 is discharged through the drip nozzle 11. When in use, the device is located in a vacuum environment as a whole, and the outlet of the drip nozzle 11 is located outside the vacuum environment. The inner wall of the drip nozzle 11 is provided with a super-hydrophobic coating. The drip nozzle 11 is detachably connected to the crucible shell 1 and can be replaced. A fluid counter-groove 12 is provided on the inner bottom wall of the crucible shell 1 at a position corresponding to the drip nozzle 11. The fluid counter-groove 12 is in an inverted cone shape and the lower end of the fluid counter-groove 12 is aligned with the upper end of the drip nozzle 11. The functional block 2 is connected, the functional block 2 is arranged in the crucible shell 1, the bottom of the functional block 2 is connected to the inner bottom wall of the crucible shell 1 through a plurality of connecting columns 21, the functional block 2 is in the shape of a cone, 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 wall of the functional block 2 and the inner wall of the crucible shell 1, the acceleration channel 41 is in the shape of a downward 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 reflux channel 43 is provided at a position corresponding to the drip nozzle 11 on the functional block 2, the reflux channel 43 is arranged in the middle position of the functional block 2 and passes through the functional block 2 up and down, the lower end of the reflux channel 43 is located directly above the fluid hedging groove 12, and the molten metal solution in the second channel 42 can return to the top of the functional block 2 through the reflux channel 43.

[0033] like Figure 1 and Figure 3As shown, the excitation coil 3 is arranged on the outer wall of the crucible shell 1, and a heat insulation block is arranged between the excitation coil 3 and the crucible shell 1. The heat insulation block is used to isolate the heat of the crucible shell 1 to protect the excitation coil 3. The excitation coil 3 is connected to a three-phase AC power supply. The number of the excitation coils 3 is a multiple of three. For example, in this embodiment, the excitation coil 3 is provided with six excitation coils, which are connected in an existing excitation coil connection manner and are divided into three phases a, b, and c. Each phase forms a closed loop, and 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°, so that the two coils of each phase are symmetrically arranged on the crucible. On the outer wall of the crucible shell 1, the angle between the projections of the coils of adjacent phases on the horizontal plane is 60°. When the excitation coil 3 is connected to an external power supply, a magnetic field is formed. The magnetic field excited by the excitation coil 3 covers the acceleration channel 41, causing the molten metal solution to rotate in the acceleration channel 41. Its centrifugal force causes the solution to accelerate along the channel. The accelerated molten metal solution moves from the periphery to the center of the second channel 42 along the second channel 42. The molten metal solution moving toward the center of the second channel 42 is collided at the fluid collision groove 12, and a part of it continues to move upward along the reflux channel 43, and the other part reaches the drip nozzle 11 downward. The molten metal solution rotates under the action of the magnetic field to fully stir the different wire solutions and mix the solutions evenly.

[0034] like Figure 1 and Figure 2As shown, an adjusting component is provided on the crucible shell 1, and the adjusting component is used to adjust the flow of the reflux channel 43. A groove is provided in the middle position of the upper end surface of the functional block 2, so that a bell mouth 431 is formed at the upper end of the reflux channel 43, and the bell mouth 431 gradually expands from bottom to top. The adjusting component includes a driving member 51, a driving rod 52 and a blocking block 53. The driving member 51 is arranged on the outer top wall of the crucible shell 1, and the driving rod 52 penetrates downwardly through the top of the crucible shell 1. The blocking block 53 is located in the crucible shell 1 and is connected to the lower end of the driving rod 52. In this embodiment, the driving member 51 includes a driving bracket 511, a linear motor 512, a working rod 513, a working slide block 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 arranged on the driving bracket 511, and 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. The working slide block 514 When the working slider 514 is no longer subjected to force, the driving rod 52 moves upward under the action of the elastic force of the working spring 517 and returns to the initial position. The driving member 51 can also adopt an existing hydraulic cylinder or a servo electric slide to drive the driving rod 52 to move up and down. A heat insulation board 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 downward and enters the crucible shell 1. The blocking block 53 is connected to the lower end of the driving rod 52. The blocking block 53 corresponds to the shape of the bell mouth 431. The blocking block 53 is in the shape of an inverted cone. An adjustment channel 432 is formed between the side wall of the blocking block 53 and the bell mouth 431. The adjustment channel 432 is annular. When the driving member 51 is working, the blocking block 53 is driven by the driving rod 52 to move up and down. When the blocking block 53 moves up and down, the cross-sectional area of ​​the adjustment channel 432 is changed. When the blocking block 53 moves down to the lower limit of the stroke, the blocking block 53 blocks the reflux channel 43, and no solution flows back upward. When the blocking 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 reflux channel 43 is the largest.

[0035] like Figure 1As shown, a wire feeding hole 13 is provided on the side wall of the crucible shell 1. The number of the wire feeding holes 13 is set to one or more. When multiple wire feeding holes 13 are provided, multiple materials can be fed simultaneously, which is convenient for manufacturing composite materials. Wire materials (which can be aluminum alloys, copper alloys, titanium alloys, etc., which can be melted by laser and can 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. The laser 6 is fixed to the side of the crucible shell 1 through an external bracket. The laser head of the laser 6 is located above the crucible shell 1 (when in use, the laser head is aligned with the crucible shell 1). The crucible shell 1 is located in a vacuum environment), the laser 6 uses an existing laser to emit high-energy-density laser, and the crucible shell 1 is provided with a laser hole 14 for the laser emitted by the laser 6 to pass through. The laser emitted by the laser 6 acts on the wire in the crucible shell 1 after passing through the laser hole 14, and the laser melts the wire. The straight line where the laser is located is located in the plane where the acceleration channel 41 is located. The laser that penetrates the wire is shot into the molten metal in the acceleration channel 41, thereby continuing to heat the molten metal in the acceleration channel 41 to completely melt the metal and form a solution. Multiple lasers 6 can be set, so that the laser acts on the wire from multiple angles and continues to heat the molten metal in the acceleration channel 41. The lasers at multiple angles are finally shot into the acceleration channel 41 to continue to heat the molten metal.

[0036] This embodiment also provides a droplet transfer method, using the above droplet transfer device based on electromagnetic drive and hydraulic adjustment, comprising the following steps:

[0037] Step 1, place the device in a vacuum environment, with the outlet of the drip nozzle 11 located outside the vacuum environment, determine whether the molten metal solution in the crucible shell 1 covers the blocking block 53, if not, feed the wire, and fuse the wire through the laser 6, the magnetic field generated by the excitation coil 3 drives the molten metal in the crucible shell 1 to rotate, and after feeding the wires of various materials, the molten metal solutions are evenly mixed under the action of the magnetic field.

[0038] Step 2: Use a temperature measuring instrument (such as a thermal imager) to confirm the distribution range of the metal inside the crucible shell 1. When the molten metal solution covers the blocking block 53 and the metal is completely melted, the driving member 51 drives the blocking block 53 to move to the upper limit of the stroke, and the fuse is suspended.

[0039] Step 3, the magnetic field generated by the excitation coil 3 causes the molten metal solution to rotate in the acceleration channel 41, and 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 to the center of the second channel 42 is collided at the fluid counter-attack groove 12, and the blocking block 53 is moved downward or the voltage and frequency of the power supply of the excitation coil 3 are adjusted to adjust the pressure at the fluid counter-attack groove 12. The molten metal solution flows out from the drip nozzle 11 to form a molten droplet transition, and the diameter of the molten droplet sprayed from the drip nozzle 11 is less than 3 mm;

[0040] Droplet transfer includes single droplet jet and liquid flow transfer;

[0041] Single-drop injection is achieved by adjusting the blocking block 53 so that the blocking block 53 quickly moves downward to the bottom, and the solution is ejected from the drip nozzle 11 under the action of the water hammer effect, thereby achieving single-drop injection, or by a sudden change in the voltage or frequency of the power supply of the excitation coil 3, the circulation is suddenly accelerated, the pressure at the upper end of the drip nozzle 11 changes, and the solution is ejected from the drip nozzle 11 under the action of the changed pressure, thereby achieving single-drop injection;

[0042] The liquid flow transition is achieved by adjusting and maintaining the voltage and frequency of the excitation coil 3, while keeping the blocking block 53 at a certain position so that the pressure at the hedging groove 12 continuously presses the solution out of the drip nozzle 11, thereby achieving continuous liquid flow transition.

[0043] Step 4: When the molten metal solution in the crucible shell 1 is lower than the blocking block 53 , continue feeding the wire.

[0044] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A droplet transfer device based on electromagnetic drive and hydraulic adjustment, characterized in that: The invention comprises a crucible shell (1) for containing molten metal, a functional block (2) arranged in the crucible shell (1), and an excitation coil (3) arranged outside the crucible shell (1); a drip nozzle (11) is arranged at the bottom of the crucible shell (1); the functional block (2) is connected to the inner wall of the crucible shell (1) through a plurality of connecting columns (21); an acceleration channel (41) is formed between the side wall of the functional block (2) and the inner 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 reflux channel (43) penetrating from top to bottom is arranged at a position on the functional block (2) corresponding to the drip nozzle (11); and an adjustment component for adjusting the flow of the reflux channel (43) is arranged on the crucible shell (1).

2. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 1 is characterized in that: A fluid counter-flow groove (12) is provided on the inner bottom wall of the crucible shell (1) at a position corresponding to the drip nozzle (11).

3. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 2 is characterized in that: A bell mouth (431) is formed at the upper end of the reflux channel (43); the adjustment component comprises a driving member (51) arranged outside the crucible shell (1), a driving rod (52) connected to the driving member (51), and a blocking block (53) connected to the driving rod (52) and corresponding to the shape of the bell mouth (431); an adjustment channel (432) is formed between a side wall of the blocking block (53) and the bell mouth (431); and the driving member (51) drives the blocking block (53) to move up and down to change the cross-sectional area of ​​the adjustment channel (432).

4. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 3 is characterized in that: The crucible shell (1) is provided with a wire feeding hole (13) for feeding a wire into the crucible shell (1), the crucible shell (1) is provided with a laser (6) aimed at the wire in the crucible shell (1), and the crucible shell (1) is provided with a laser hole (14) for laser light emitted by the laser (6) to pass through.

5. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 4 is characterized in that: The laser (6) shines laser light on the wire material, and the laser light that penetrates the wire material is injected into the molten metal in the acceleration channel (41).

6. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 4 is characterized in that: The acceleration channel (41) is in the shape of a trumpet with the mouth facing downward.

7. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 4 is characterized in that: A heat insulation block is provided between the excitation coil (3) and the crucible shell (1).

8. The droplet transfer device based on electromagnetic drive and hydraulic adjustment according to claim 4 is characterized in that: The inner wall of the drip nozzle (11) is provided with a super-hydrophobic coating.

9. A droplet transfer method, using a droplet transfer device based on electromagnetic drive and hydraulic regulation as claimed in any one of claims 3 to 8, characterized in that: The following steps are involved: Step 1: Place the device in a vacuum environment to determine whether the molten metal solution in the crucible shell (1) covers the blocking block (53). If not, feed the wire and fuse it through the laser (6). The magnetic field generated by the excitation coil (3) drives the molten metal in the crucible shell (1) to rotate. Step 2: When the molten metal covers the blocking block (53) and the metal is completely melted, the driving member (51) drives the blocking block (53) to move to the top of the stroke, and the fuse is suspended; Step 3: The magnetic field generated by the excitation coil (3) causes the molten metal solution to rotate in the acceleration channel (41), and its centrifugal force causes the solution to accelerate along the channel, and finally collide at the fluid counter-collision groove (12), and the blocking block (53) is moved downward or the voltage and frequency of the excitation coil (3) are adjusted to adjust the pressure at the fluid counter-collision groove (12), and the solution flows out from the drip nozzle (11), forming a molten droplet transition; Step 4: When the molten metal solution in the crucible shell (1) is lower than the blocking block (53), continue feeding the wire.

10. The droplet transfer method according to claim 9, characterized in that: The droplet transfer in step 3 includes two types: single droplet injection and liquid flow transfer; The single-drop injection is achieved by adjusting the blocking block (53) so that the blocking block (53) is quickly moved downward to the bottom, and the solution is ejected from the drip nozzle (11) under the action of the water hammer effect, thereby achieving the single-drop injection; The liquid flow transition is achieved by adjusting the voltage and frequency of the excitation coil (3) and keeping the blocking block (53) at a certain position so that the pressure at the offset groove (12) continuously presses the solution out from the drip nozzle (11), thereby achieving continuous liquid flow transition.

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