Powder feeding device for MIM powder

Abstract

The invention belongs to the field of powder feeding, and particularly relates to a powder feeding device for MIM powder, the powder feeding device comprises a powder outlet assembly and a powder feeding track, the powder outlet assembly is used for uniformly conveying the MIM powder to the powder feeding track, the powder feeding track is wrapped with a sealing assembly, the sealing assembly is wrapped on the powder feeding track to form a sealed powder feeding space, and the powder feeding space is provided with a sealing cavity. A powder inlet is formed in the sealing assembly and used for guiding the MIM powder from the powder outlet assembly into the powder feeding space; an air outlet is formed in the side, away from the powder inlet, of the powder feeding rail, an air feeding pipe is arranged at the bottom of the air outlet, a powder feeding pipe is arranged at the position, corresponding to the air outlet, of the sealing assembly, and the air feeding pipe is used for blowing air into the powder feeding space, so that the MIM powder passing through the air outlet enters the powder feeding pipe. The powder feeding amount can be increased, so that the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of powder feeding, and in particular relates to a powder feeding device for MIM powder, specifically to a powder feeding device for MIM powder with a particle size less than 20um, and the device can also be used as a powder feeding device for powder spheroidizing equipment. Background Art

[0002] MIM (Metal Injection Molding) technology is a molding method in which a plasticized mixture of metal powder and its binder is injected into a mold. It first mixes the selected metal powder with the binder, then granulates the mixture and injects it into the required shape. The MIM process includes at least mixing, molding, degreasing and sintering. The sintered surface is selectively treated according to needs to quickly manufacture high-density, high-precision and complex structural parts. The particle size of the metal powder used in MIM is generally 0.5-20μm. MIM powder is mostly obtained by screening the ball powder produced by the atomization method. Since the atomization method uses rods and wires as raw materials, the use of gas to disperse the molten metal droplets will cause adhesion between the ball powders, that is, satellite balls, so it is necessary to develop a spheroidizing equipment using powder as raw material.

[0003] Theoretically, the finer the powder, the larger the specific surface area, the easier it is to form and sinter. However, the finer the powder, the worse the fluidity and the easier it is to agglomerate. When increasing production capacity, it is easy to cause powder blockage in the powder feeding pipe and interrupt production. It needs to be cleaned before it can be reused, resulting in low production efficiency. In addition, the powder feeding capacity of the equipment currently suitable for particle size <20um is usually <2Kg / h, which further limits production efficiency. In order to improve production efficiency, it is necessary to develop a set of equipment that can feed a large amount of powder. Summary of the invention

[0004] In order to improve the deficiencies of the prior art, the present invention provides a powder feeding device for MIM powder, which can increase the powder feeding amount and thus improve production efficiency.

[0005] The present invention provides a powder feeding device for MIM powder, comprising a powder discharge assembly and a powder feeding track, wherein the powder discharge assembly is used to uniformly convey the MIM powder to the powder feeding track, the powder feeding track is surrounded by a closed assembly, the closed assembly is surrounded by the powder feeding track to form a closed powder feeding space, and a powder inlet is provided on the closed assembly to introduce the MIM powder from the powder discharge assembly into the powder feeding space;

[0006] An air outlet is arranged on one side of the powder feeding track away from the powder inlet, an air supply pipe is arranged at the bottom of the air outlet, and a powder supply pipe is arranged at a position corresponding to the air outlet on the closed component. The air supply pipe is used to blow air into the powder feeding space so that the MIM powder passing through the air outlet enters the powder supply pipe.

[0007] According to an embodiment of the present invention, a plurality of protrusions are provided on the powder feeding track, and the protrusions are used to collide with the powder to destroy the agglomerated powder.

[0008] According to an embodiment of the present invention, the protrusion structure is a triangular prism structure, and one edge of the triangular prism structure is arranged facing the powder outlet. When the powder passes through the protrusion structure, it collides with the edge of the triangular prism structure, which can destroy the agglomeration characteristics of the powder.

[0009] According to an embodiment of the present invention, the angle corresponding to the edge is 15 to 30 degrees.

[0010] According to an embodiment of the present invention, the height of the triangular structure is 10 to 30 mm, and the bottom area of ​​the triangular structure is 0.2 to 1 cm 2 For example, the height of the triangular structure is 20 mm, and the bottom area of ​​the triangular structure is 0.5 cm 2 .

[0011] According to an embodiment of the present invention, the powder feeding device is used to feed powder with a particle size less than 20 μm, such as metal powder with a particle size of 0.5 to 20 μm.

[0012] According to an embodiment of the present invention, the enclosed component includes a top plate arranged above the powder feeding track, a side plate is arranged between the powder feeding track and the top plate, the powder feeding track, the top plate and the side plate constitute a closed powder feeding space, and a powder inlet is arranged on the top plate for introducing the MIM powder from the powder discharge component into the powder feeding space.

[0013] According to an embodiment of the present invention, a second vibrator is provided at the bottom of the powder feeding track for vibrating and driving the MIM powder to run on the powder feeding track.

[0014] According to an embodiment of the present invention, the air outlet is provided with a filter plate, and the filter plate is used to prevent MIM powder from falling into the air supply pipe and blocking the air supply pipe.

[0015] According to an embodiment of the present invention, a powder guiding mechanism is provided at the bottom of the top plate, and the powder guiding mechanism is provided at the inlet of the powder feeding pipe. The powder guiding mechanism is used to guide the MIM powder blown up by the air feeding pipe into the powder feeding pipe to prevent the blown MIM powder from diffusing.

[0016] According to an embodiment of the present invention, the powder guiding mechanism is a trumpet structure, or is formed by two or more plate-like structures arranged opposite to each other. Preferably, the plate-like structures are arranged obliquely to form a funnel-shaped structure that is small at the top and large at the bottom.

[0017] As an example, the powder guiding mechanism is a trumpet structure wrapped around the outer circumference of the powder feeding pipe, and the distance between the bottom of the trumpet structure and the powder feeding track is 5 to 10 mm, for example, 8 mm.

[0018] According to an embodiment of the present invention, the distance between the powder feeding track and the top plate, that is, the height of the powder feeding space is 15-25 mm, for example, 20 mm.

[0019] According to an embodiment of the present invention, the air delivery pipe is connected to an external gas source and is used to introduce inert gas into the air delivery pipe to blow the MIM powder passing through the top of the air delivery pipe into the powder delivery pipe;

[0020] According to an embodiment of the present invention, the powder delivery pipe is connected to the spheroidizing device, the air delivery pipe is at a positive pressure relative to the powder delivery pipe, and the air delivery pipe can deliver powder into the powder delivery pipe.

[0021] According to an embodiment of the present invention, the diameter ratio of the air delivery pipe to the powder delivery pipe is 1:(1-2), for example, 3:4.

[0022] According to an embodiment of the present invention, a projection of the center of the powder delivery pipe on the air delivery pipe coincides with the center of the air delivery pipe.

[0023] According to an embodiment of the present invention, the diameter of the air delivery pipe is 6 mm, and the diameter of the powder delivery pipe is 8 mm.

[0024] According to an embodiment of the present invention, the powder output assembly includes a powder tank, a powder box and a first vibrator which are sequentially arranged from top to bottom, the powder box is arranged at the bottom of the powder tank, and the first vibrator is fixed to the lower surface of the powder box.

[0025] According to an embodiment of the present invention, the bottom of the powder box can be a parallel structure or an inclined structure. When it is a parallel structure, the first vibrator is a linear vibrator; when the powder box 2 is inclined, the inclination angle is 30 to 60°, for example, 45°.

[0026] According to an embodiment of the present invention, the powder box has a hollow structure for containing the MIM powder flowing from the powder tank, and a powder outlet is provided on one side of the powder box.

[0027] According to an embodiment of the present invention, the height of the powder outlet is 1 / 3 to 2 / 3 of the height of the powder box, and the bottom of the powder outlet is in the same plane as the bottom of the powder box.

[0028] According to an embodiment of the present invention, a guide plate is provided at the bottom of the powder outlet, and the guide plate is used to guide the MIM powder output from the powder outlet into the powder feeding space.

[0029] According to an embodiment of the present invention, the guide plate is tilted, and the tilt angle is 10-45°, for example, 30°.

[0030] According to an embodiment of the present invention, the guide plate is a sealing structure, and the guide plate structure is configured as a tubular structure extending from the powder outlet to the powder inlet. The cross-section of the tubular structure can be circular, elliptical, rectangular or other structures, for example, a rectangular structure.

[0031] According to an embodiment of the present invention, the guide plate is detachably connected to the powder outlet, and a sealing member is provided between the guide plate and the powder outlet.

[0032] Beneficial Effects

[0033] 1) The powder feeding device for MIM powder in the present invention comprises a powder discharge assembly and a powder feeding track, wherein the powder discharge assembly is used to uniformly transport the MIM powder to the powder feeding track, the closed assembly surrounds the powder feeding track to form a closed powder feeding space, an air outlet is arranged on the side of the powder feeding track away from the powder inlet, an air feeding pipe is arranged at the bottom of the air outlet, and a powder feeding pipe is arranged at a position corresponding to the air outlet on the closed assembly, and the air feeding pipe is used to blow air into the powder feeding space so that the MIM powder passing through the air outlet enters the powder feeding pipe; the present invention realizes powder feeding through the closed powder feeding space, which can prevent water vapor, oxygen and the like in the external environment from contaminating the MIM powder and causing oxidation agglomeration of the MIM powder. At the same time, the powder feeding method of blowing air can disperse the agglomerated powder clumps, and even when a large amount of powder is fed, the powder entering the powder feeding pipe can be in a completely dispersed state, thereby preventing the powder from clogging the pipeline and effectively improving the production efficiency.

[0034] 2) The powder feeding device for MIM powder in the present invention has a plurality of protrusions on the powder feeding track. The protrusions are triangular prisms, and one edge of the triangular prism faces the powder outlet. When the powder passes through the protrusions, it collides with the edge of the triangular prism, which can destroy the agglomeration characteristics of the powder, thereby preventing the powder from agglomerating on the powder feeding track, greatly improving the production efficiency. The powder feeding device of the present invention can deliver a powder amount of 6Kg / h, which is much greater than the 2Kg / h powder delivery amount on the existing market. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of the powder feeding device for MIM powder in Example 1;

[0036] Figure 2 Schematic diagram of the structure of the protruding tissue.

[0037] In the figure, 1-powder tank, 2-powder box, 3-powder outlet, 4-first vibrator, 5-powder feeding track, 6-air feeding pipe, 7-powder feeding pipe, 8-second vibrator, 9-top plate, 10-filter plate, 11-guide plate, 12-powder guiding mechanism, 13-protruding structure. DETAILED DESCRIPTION

[0038] The structure of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0039] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Example 1

[0042] The powder feeding device for MIM powder in this embodiment is used to transport powder with a particle size less than 20um. The powder feeding device includes a powder discharge assembly and a powder feeding track 5. The powder discharge assembly is used to uniformly transport the MIM powder to the powder feeding track 5. The powder discharge assembly includes a powder tank 1, a powder box 2 and a first vibrator 4 arranged in sequence from top to bottom. The powder box 2 is arranged at the bottom of the powder tank 1, and the first vibrator 4 is fixed to the lower surface of the powder box 2.

[0043] The bottom of the powder box 2 can be a parallel structure or an inclined structure. When it is a parallel structure, the first vibrator 4 uses a linear vibrator; when the powder box 2 is inclined, the inclination angle is set according to actual needs, for example, 30 to 60 degrees, for example, 45 degrees.

[0044] The powder box 2 has a hollow structure for containing the MIM powder flowing in from the powder tank 1. A powder outlet 3 is provided on one side of the powder box 2. The height of the powder outlet 3 is 1 / 3 to 2 / 3 of the height of the powder box 2. The bottom of the powder outlet 3 is located in the same plane as the bottom of the powder box 2. The size of the powder outlet 3 can be adjusted according to actual needs.

[0045] A guide plate 11 is provided at the bottom of the powder outlet 3. The guide plate 11 is tilted. The tilt angle is set according to actual needs and can be 10 to 45 degrees, for example, 30 degrees. The guide plate 11 is used to guide the MIM powder out of the powder outlet 3. In order to prevent the MIM powder from diffusing in the air, the guide plate 11 can be set as a sealing structure, that is, the guide plate structure 11 is set as a tubular structure extending from the powder outlet 3. The cross-section of the tubular structure can be circular, elliptical, rectangular or other structures, for example, a rectangular structure.

[0046] The guide plate 11 is detachably connected to the powder outlet 3 . A suitable guide plate 11 is selected according to the size of the powder outlet 3 , and a sealing member is provided between the guide plate 11 and the powder outlet 3 .

[0047] The powder feeding track 5 is arranged on one side of the powder box 2 close to the powder outlet 3, a top plate 9 is arranged on the top of the powder feeding track 5, a second vibrator 8 is arranged on the bottom, a side plate is arranged between the powder feeding track 5 and the top plate 9, the powder feeding track 5, the top plate 9 and the side plates constitute a closed powder feeding space, a powder inlet is arranged at the position corresponding to the top plate 9 and the guide plate 11, the guide plate 11 penetrates into the powder feeding space through the powder inlet, and the penetration depth is at least half of the height of the powder feeding space.

[0048] The distance between the powder feeding track 5 and the top plate 9, that is, the height of the powder feeding space is 15-25 mm, for example, 20 mm.

[0049] An air delivery pipe 6 is provided on the side of the powder delivery track 5 away from the powder inlet, a powder delivery pipe 7 is provided on the top plate 9 at a position corresponding to the air delivery pipe 6, a filter 10 is provided on the top of the air delivery pipe 6, and a powder guiding mechanism 12 is provided at the bottom of the top plate 9. The powder guiding mechanism 12 is arranged at the entrance of the powder delivery pipe 7. The powder guiding mechanism 12 is used to guide the MIM powder blown up by the air delivery pipe 6 into the powder delivery pipe 7 to avoid the diffusion of the blown MIM powder. The structure of the powder guiding mechanism 12 can be set according to actual needs, for example, a horn structure, or two or more relatively arranged plate structures are surrounded, wherein the plate structure is arranged obliquely to form a funnel-shaped structure with a small top and a large bottom. For example, the powder guiding mechanism 12 is set as a horn structure wrapped around the outer periphery of the powder delivery pipe 7, and the distance between the bottom of the horn structure and the powder delivery track 5 is about 8 mm, so that the MIM powder can all enter the powder delivery pipe 7 after being blown.

[0050] The air delivery pipe 6 is connected to an external air source, and is used to pass inert gas into the air delivery pipe 6, and blow the MIM powder passing through the top of the air delivery pipe 6 into the powder delivery pipe 7; the powder delivery pipe 7 is connected to the spheroidizing device, and both the powder delivery pipe 7 and the spheroidizing device are in a negative pressure state, so the air delivery pipe 6 is also in a negative pressure state. Since the air delivery pipe 6 is at a positive pressure relative to the powder delivery pipe 7, the air delivery pipe can deliver the powder into the powder delivery pipe.

[0051] The diameters of the air delivery pipe 6 and the powder delivery pipe 7 are set according to actual needs. The projection of the center of the powder delivery pipe 7 on the air delivery pipe 6 coincides with the center of the air delivery pipe 6. The diameter ratio of the air delivery pipe 6 to the powder delivery pipe 7 is 1:(1-2), for example, 3:4.

[0052] In this embodiment, the diameter of the air delivery pipe 6 is 6 mm, and the diameter of the powder delivery pipe 7 is 8 mm.

[0053] See also Figure 2 As shown, a plurality of protrusions 13 are arranged on the powder feeding track 5. The protrusions 13 are triangular structures, and one edge of the triangular structure faces the powder outlet 3. When the powder passes through the protrusions 13, it collides with the edge of the triangular structure, which can destroy the agglomeration characteristics of the powder. The angle corresponding to the edge is 15 to 30°. The smaller the angle, the better the effect. The number and size of the protrusions 13 can be set according to actual conditions. In this embodiment, the height of the triangular structure is 10 to 30 mm, and the bottom area of ​​the triangular structure is 0.2 to 1 cm 2 For example, the height of the triangular structure is 20 mm, and the bottom area of ​​the triangular structure is 0.5 cm 2 .

[0054] In actual use, the powder delivery amount is adjusted in real time by adjusting the size of the powder outlet 3, the vibration parameters of the first vibrator 4 and the second vibrator 8, and the flow rate of the gas in the air delivery pipe 6.

[0055] The principle of the present invention is as follows: the powder feeding track 5 is fixed on the second vibrator 8, and the powder falls from the powder outlet 3 onto the powder feeding track 5. Under the vibration of the second vibrator 8, the powder continues to be transmitted forward. A convex edge structure is provided on the powder feeding track 5, which can destroy the agglomeration characteristics of the powder. An air supply port is opened at the end of the powder feeding track 5. When the powder moves to the air supply port, the air supply pipe 6 blows air to the air supply port through the small holes on the filter plate 10 to further disperse the powder. The function of the filter plate 10 is to prevent the powder from flowing back into the air supply pipe 6. The dispersed powder is sucked into the powder feeding pipe 7 directly above (the powder feeding pipe 7 is at negative pressure relative to the air feeding pipe 6). The powder feeding pipe 7 is connected to the powder spheroidizing equipment to introduce the MIM powder into the powder spheroidizing equipment for spheroidization.

[0056] A method for powder feeding using the above powder feeding device comprises the following steps:

[0057] 1. Connect the powder feeding device to the powder spheroidizing equipment with the powder feeding pipe 7, and evacuate the air to put the whole system in a vacuum state.

[0058] 2. Start the first vibrator 4 and adjust the width of the powder outlet 3 so that the powder dropped from the powder tank 1 falls from the powder outlet 3 onto the powder feeding track 5 .

[0059] 3. The second vibrator 8 is started, and the powder falling onto the powder feeding track 5 is transmitted by the powder feeding track 5, so that the agglomeration characteristics of the powder are further reduced.

[0060] 4. Input a certain flow of argon gas into the gas supply pipe 6.

[0061] 5. When the powder reaches the air delivery port at the end of the powder delivery track 5, it is blown away by the argon gas and sucked into the powder delivery pipe 7, thereby entering the powder spheroidizing equipment.

[0062] The parameters of this embodiment are set as follows: the particle size of the titanium powder in the powder tank 1 is less than 20um, the vibration frequency of the first vibrator 4 is 45Hz, the vibration frequency of the second vibrator 8 is 53Hz, the argon flow rate is adjusted to 8L / min, and the powder delivery rate is 6Kg / h.

[0063] The above examples are used to illustrate the specific implementation of the present invention. However, the protection scope of the present invention is not limited to the above exemplary implementation. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A powder feeding device for MIM powder, characterized in that: It includes a powder discharge assembly and a powder feeding track, wherein the powder discharge assembly is used to uniformly transport the MIM powder to the powder feeding track, the powder feeding track is surrounded by a closed assembly, the closed assembly is surrounded by the powder feeding track to form a closed powder feeding space, and the closed assembly is provided with a powder inlet for introducing the MIM powder from the powder discharge assembly into the powder feeding space; An air outlet is arranged on one side of the powder feeding track away from the powder inlet, an air supply pipe is arranged at the bottom of the air outlet, and a powder supply pipe is arranged at a position corresponding to the air outlet on the closed component. The air supply pipe is used to blow air into the powder feeding space so that the MIM powder passing through the air outlet enters the powder supply pipe.

2. The powder feeding device for MIM powder according to claim 1, characterized in that: A plurality of protrusions are arranged on the powder feeding track, and the protrusions are used to collide with the powder to destroy the agglomerated powder. Preferably, the protrusion structure is a triangular prism structure, and one edge of the triangular prism structure is arranged facing the powder outlet. When the powder passes through the protrusion structure, it collides with the edge of the triangular prism structure, which can destroy the agglomeration characteristics of the powder. According to an embodiment of the present invention, the angle corresponding to the edge is 15 to 30 degrees.

3. The powder feeding device for MIM powder according to claim 1, characterized in that: The enclosed component includes a top plate arranged above the powder feeding track, a side plate is arranged between the powder feeding track and the top plate, the powder feeding track, the top plate and the side plate constitute a closed powder feeding space, and a powder inlet is arranged on the top plate for introducing the MIM powder from the powder discharge component into the powder feeding space. Preferably, a second vibrator is provided at the bottom of the powder feeding track for vibrating and driving the MIM powder to run on the powder feeding track.

4. The powder feeding device for MIM powder according to any one of claims 1 to 3, characterized in that: The air outlet is provided with a filter sheet, and the filter sheet is used to prevent MIM powder from falling into the air supply pipe and blocking the air supply pipe.

5. The powder feeding device for MIM powder according to any one of claims 1 to 3, characterized in that: A powder guiding mechanism is provided at the bottom of the top plate. The powder guiding mechanism is provided at the inlet of the powder feeding pipe and is used to guide the MIM powder blown up by the air feeding pipe into the powder feeding pipe to prevent the blown MIM powder from diffusing. Preferably, the powder guiding mechanism is a trumpet structure, or is formed by two or more plate-like structures arranged opposite to each other.

6. The powder feeding device for MIM powder according to any one of claims 1 to 3, characterized in that: The air delivery pipe is connected to an external air source and is used to introduce inert gas into the air delivery pipe to blow the MIM powder passing through the top of the air delivery pipe into the powder delivery pipe; the powder delivery pipe is connected to the spheroidizing equipment, the air delivery pipe is at a positive pressure relative to the powder delivery pipe, and the air delivery pipe can deliver powder into the powder delivery pipe. Preferably, the diameter ratio of the air delivery pipe to the powder delivery pipe is 1:(1-2).

7. The powder feeding device for MIM powder according to any one of claims 1 to 3, characterized in that: The powder output assembly comprises a powder tank, a powder box and a first vibrator which are arranged in sequence from top to bottom. The powder box is arranged at the bottom of the powder tank, and the first vibrator is fixed on the lower surface of the powder box.

8. The powder feeding device for MIM powder according to claim 7, characterized in that: The powder box has a hollow structure for accommodating MIM powder flowing from the powder tank. A powder outlet is provided on one side of the powder box. The height of the powder outlet is 1 / 3 to 2 / 3 of the height of the powder box. The bottom of the powder outlet is in the same plane as the bottom of the powder box.

9. The powder feeding device for MIM powder according to claim 8, characterized in that: A guide plate is arranged at the bottom of the powder outlet, and the guide plate is used to guide the MIM powder output from the powder outlet into the powder feeding space. The guide plate is arranged tilted, and the tilt angle is 10 to 45 degrees.

10. The powder feeding device for MIM powder according to claim 8, characterized in that: The guide plate is a sealing structure, and the guide plate structure is configured as a tubular structure extending from the powder outlet to the powder inlet. The cross section of the tubular structure may be circular, elliptical, rectangular or other structures.

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