CN115740508A - Powder supply device and powder supply method for additive machining - Google Patents

Abstract

The invention relates to the technical field of additive manufacturing, in particular to a powder supply device and a powder supply method for additive processing, which comprise the following steps: the printing powder bin is used for containing printing powder; a filling powder bin for containing filling powder; the powder sieving component comprises a sieve plate, a first powder discharge port positioned at the lower layer of the sieve plate and a second powder discharge port positioned at the upper layer of the sieve plate; the forming cylinder is arranged above the powder sieving component; and the scraper component is used for scraping the printing powder in the printing powder bin and the filling powder in the filling powder bin to the surface of the forming cylinder. The printing powder in the forming cylinder is poured during printing, and is recycled and added into the printing powder bin through screening, in the process, the filling powder in the filling bin is used for refilling to a preset height, so that the printing powder is always positioned in a height layer near a printing layer, and participates in the powder sintering process, the continuous powder supply of the printing powder is kept, and the total consumption of the printing powder is reduced, so that the processing cost is saved.

Description

Powder supply device and powder supply method for additive machining

Technical Field

The invention relates to the technical field of additive manufacturing, in particular to a powder supply device and a powder supply method for additive processing.

Background

The selective laser melting is an additive manufacturing technology, which utilizes computer-aided design and manufacturing, based on the principle of 'discrete-layering-accumulation', utilizes high-energy laser beams to directly melt and form metal powder into a fully-compact three-dimensional part, does not need a die in the forming process, is not limited by the structural complexity of the part, and can be used as a supporting material to obtain a metal functional part with metallurgical bonding, high precision and high structural complexity, thereby having wide application prospect.

The specific principle is as follows: before a laser beam starts scanning, a powder spreading device firstly pushes metal powder to a substrate of a forming cylinder in a flatwise mode, the laser beam selectively melts the powder on the substrate according to a filling scanning line of a current layer, the current layer is processed, then the substrate of the forming cylinder descends by a distance of 1 layer thickness, a powder cylinder ascends by a distance of a certain thickness, the powder spreading device spreads the metal powder on the processed current layer, equipment is adjusted to data of the profile of the next layer for processing, and the processing is carried out layer by layer until the whole part is processed. The whole process is carried out in a processing chamber which is protected by inert gas so as to avoid the reaction of the metal and other gases at high temperature.

In the additive machining of some large-size workpieces and with high requirements on machining precision, a 3D printing technology of selective laser melting is generally adopted for machining, and because powder spreading and printing layer by layer requires a large amount of powder, the manufacturing cost is increased, and therefore, for large-size powder spreading machining, how to reduce the use amount of printing powder becomes a problem that people want to solve.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a powder supply apparatus for additive manufacturing, comprising:

the printing powder bin is used for containing printing powder;

a filling powder bin for containing filling powder;

the powder screening component comprises a sieve plate, a first powder discharge port positioned on the lower layer of the sieve plate and a second powder discharge port positioned on the upper layer of the sieve plate;

the forming cylinder is arranged above the powder sieving component;

the scraper component is used for scraping the printing powder in the printing powder bin and the filling powder in the filling powder bin to the surface of the forming cylinder to enable the powder to be flat;

the position changing machine is arranged at the bottom of the forming cylinder and can drive the forming cylinder to turn over so as to enable powder in the forming cylinder to be poured onto the surface of the powder screening component;

the first powder receiving cylinder is connected to the first powder discharging port;

the second powder receiving cylinder is connected to the second powder discharge port;

wherein, sieve powder part, shaping jar, scraper part and machine of shifting set up in the seal box, inert shielding gas has in the seal box, first connect a powder section of thick bamboo be used for to print the powder storehouse and supply the powder, the second connects a powder section of thick bamboo to be used for supplying the powder to filling the powder storehouse.

Preferably, the sieve plate is arranged in a manner of inclining to the horizontal plane, the second powder discharge port is arranged at the low position of the sieve plate, a collecting hopper is arranged below the sieve plate, and the first powder discharge port is arranged at the bottom of the collecting hopper.

Preferably, a vibrating motor is arranged on the sieve plate.

Preferably, the first powder discharging port and the second powder discharging port are both provided with valves, and the valves are used for controlling the on-off of the first powder discharging port or the second powder discharging port.

Preferably, a first powder pumping pipeline is arranged between the first powder receiving cylinder and the printing powder bin, a first powder absorber is arranged on the first powder pumping pipeline, and the first powder absorber is used for absorbing the printing powder in the first powder receiving cylinder into the printing powder bin; and a second powder pumping pipeline is arranged between the second powder receiving cylinder and the filling powder bin, a second powder suction device is arranged on the second powder pumping pipeline, and the second powder suction device is used for sucking the filling powder in the second powder receiving cylinder into the filling powder bin.

Preferably, first connect a powder section of thick bamboo and second to connect a powder section of thick bamboo all including transition feed bin and confession powder feed bin, the transition feed bin is located supply the top of powder feed bin, the transition feed bin with supply to be equipped with the isolating valve between the powder feed bin, be equipped with the gas washing valve on the transition feed bin, be used for right the transition feed bin takes a breath, makes the transition feed bin and supplies the powder feed bin to have the same atmosphere environment.

Preferably, inhale the powder ware including album powder case, inhale powder entry, powder export and air current export, the collection powder incasement is equipped with an album powder chamber, inhale the first end connection powder extraction pipeline of powder entry, the powder chamber that gathers is connected to the second end, the powder export is located the bottom in album powder chamber, the first end of air current export is connected to the upper portion in album powder chamber, the second end of air current export is connected to in the seal box.

Preferably, the positioner comprises a first support frame and a second support frame, the second support frame is arranged on the inner side of the first support frame and can be driven by a turnover driver to turn over relative to the first support frame along a Y axis, and the forming cylinder is connected to the second support frame and is turned over along the Y axis.

Preferably, the forming cylinder is detachably connected with the second support frame.

The second aspect of the invention provides a technical scheme, and the powder supply method for additive machining comprises the following steps:

step 1, defining the quantity of prepared printing powder as Q, the quantity of filling powder as E, and the maximum volume of a forming cylinder as W, wherein Q is less than W, Q + E > W, and turning over the forming cylinder to pour the powder in the forming cylinder to a powder screening component when the additive height H1 is increased (the volume change of the forming cylinder is W1), wherein Q is less than W1;

step 2, collecting the printing powder screened by the powder screening component, refilling the printing powder into the printing powder bin, collecting the filling powder screened by the powder screening component, and filling the filling powder into the filling powder bin;

step 3, backfilling the filling powder in the filling powder bin into the forming cylinder, wherein the backfilled filling powder is smaller than W1;

and 4, continuously increasing the material by using the printing powder recovered from the printing powder bin, and repeating the steps 1-3 until the printing is finished.

Preferably, in step 2, refilling the printing powder into the printing powder bin comprises the following method:

the method a comprises the steps that a powder receiving cylinder is used for collecting printing powder and filling powder which are screened by a powder screening component, the printing powder collected in the powder receiving cylinder is recovered to a printing powder bin in a suction mode, and the filling powder collected in the powder receiving cylinder is recovered to a filling powder bin;

and b, collecting the printing powder and the filling powder which are screened by the powder screening component by using a powder receiving cylinder, recovering the printing powder collected in the powder receiving cylinder to a printing powder bin by using a mechanical lifting conveying mode, and recovering the filling powder collected in the powder receiving cylinder to a filling powder bin.

Preferably, in the method a, the air flow of the air exhaust is discharged outside the sealing box, the powder receiving cylinder comprises a transition bin and a powder supply bin, when the powder is sucked to the transition bin from the powder receiving cylinder, the transition bin and the powder supply bin are in an isolation state, after the suction action is stopped, the transition bin is subjected to air washing, the transition bin and the powder supply bin are enabled to have the same atmosphere environment, then the transition bin and the powder supply bin are communicated, and the powder in the transition bin enters the powder supply bin.

Compared with the prior art, the powder supply device and the powder supply method for additive machining have the remarkable advantages that:

in the powder supply device for additive processing, the printing powder in the forming cylinder is poured and recycled and added into the printing powder bin through screening in the printing process, and the filling powder in the filling bin is used for backfilling to a preset height in the process, so that the printing powder is always positioned in a height layer near a printing layer and participates in the powder sintering process, the continuous powder supply of the printing powder is kept, and the total consumption of the printing powder is reduced, so that the processing cost is saved.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural diagram of a powder supply device for additive manufacturing according to the present invention;

FIG. 2 is a schematic view of the forming cylinder of the present invention;

FIG. 3 is a schematic illustration of the forming cylinder of the present invention in a top view relationship with the screen deck;

FIG. 4 is a schematic illustration of the forming cylinder of the present invention shown in a side view positional relationship with a screen deck;

FIG. 5 is a schematic view of the forming cylinder shown in the inverted condition of the present invention;

FIG. 6 is a schematic structural view of a powder collecting chamber according to the present invention;

FIG. 7 is another schematic structural diagram of a powder supply device for additive manufacturing according to the present invention;

fig. 8 is a schematic structural view of the printing powder bin according to the present invention.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

The processing mode of powder spreading additive printing determines that the larger the outer contour volume of a workpiece is, the larger the required powder amount is, and when the wall thickness of the workpiece is thinner, the powder amount required by actual sintering is less, so that the powder with large powder amount is filled, the utilization rate of the powder is low, and the technical problem to be solved by the invention is how to use the small powder amount to ensure continuous supply in the powder spreading printing process.

Aiming at the processing mode of layer-by-layer sintering forming of powder spreading and printing, the invention aims to reduce the total usage amount of printing powder, and gradually and completely sinter the printing powder to form a workpiece body by pouring the powder in the forming cylinder for multiple times and recycling the printing powder-refilling and filling the powder in a mode of recycling the printing powder and not sintering most of the powder at the bottom layer.

[ powder supply device for additive processing ]

According to the first aspect of the invention, a powder supply device for additive machining is provided, as shown in fig. 1, a powder sieving component 50, a forming cylinder 30, a scraper component 61 and a position changer 40 are arranged in a seal box 100, an additive space 101 in the seal box 100 is provided with inert protective gas, powder is not oxidized in the powder laying and additive machining process, the position changer 40 is arranged on a bearing seat 20, the forming cylinder 30 is arranged on the position changer 40, and the forming cylinder 30 is supplied with powder through a powder bin and the scraper component 61.

The printing powder bin 52 is used for containing printing powder, the filling powder bin 53 is used for containing filling powder, the printing powder bin 52 provides printing powder for the scraper component 61 in powder laying printing and is scraped flat on the surface of the forming cylinder 30 by the scraper component 61, and the filling powder bin 53 provides filling powder for the scraper component 61 in powder laying printing and is scraped flat on the surface of the forming cylinder 30 by the scraper component 61.

In order to timely recover powder, the forming cylinder 30 is arranged above the powder sieving component 50, the positioner 40 can drive the forming cylinder 30 to overturn, so that the powder in the forming cylinder 30 is poured out, the poured powder is sieved by the powder sieving component 50, the printing powder is refilled into the printing powder bin 52, and the printing powder continues to participate in subsequent powder paving and printing work.

The powder sieving component 50 comprises a sieve plate 51, a first powder discharging port 512 at the lower layer of the sieve plate 51 and a second powder discharging port 511 at the upper layer of the sieve plate 51, wherein the powder sieving component 50 sieves printing powder to the first powder discharging port 512 and filler powder to the second powder discharging port 511.

Further, a first powder receiving cylinder 57 is connected to the first powder discharging port 512, and a second powder receiving cylinder 58 is connected to the second powder discharging port 511, wherein the first powder receiving cylinder 57 is used for supplying powder to the printing powder bin 52, and the second powder receiving cylinder 58 is used for supplying powder to the filling powder bin 53.

As shown in fig. 2 to 5, the positioner 40 includes a first support frame 41 and a second support frame 42, the second support frame 42 is disposed inside the first support frame 41 and can be driven by a turning drive 43 to turn in the Y-axis direction with respect to the first support frame 41, and the forming cylinder 30 is connected to the second support frame 42 so that the forming cylinder 30 is turned in the Y-axis direction.

In the preferred embodiment, the first and second support brackets 41, 42 are provided in a U-shape, and the forming cylinder 30 is mounted to the second support bracket 42 at a middle position thereof. Therefore, the first support frame 41, the second support frame 42 and the forming cylinder 30 are compact in structure, and the whole volume of the equipment can be reduced.

Wherein, the turning driver 43 can be selected as a servo motor with a gearbox, and can accurately control the turning angle of the forming cylinder 30.

Preferably, the forming cylinder 30 is removably attached to the second support bracket 42. In this way, the molding cylinder 30 of a different size can be replaced according to the size of the printed part.

Referring to fig. 3, the forming cylinder 30 includes a cylinder 31 and a substrate 32, the cylinder 31 has a cavity therein, the substrate 32 can move up and down in the cavity to lay powder layer by layer, the scraper 61 moves back and forth on the upper end 311 of the cylinder 31 to scrape the powder evenly on the upper end 311 of the cylinder 31, and the laser 13 sinters the powder in a predetermined path on a plane to form a solid structure.

Further, since the base plate 32 is driven by the bottom electric cylinder, in order to supply power to the bottom electric cylinder of the base plate 32 in a rotating state, a power supply line is pre-buried between the first support frame 41 and the second support frame 42, and a conductive slip ring is disposed at the rotating shaft 421 of the first support frame 41 and the second support frame 42 to ensure that the power is supplied to the electric cylinder in the rotating state.

Preferably, the end of the power supply line is provided with a plug 451, the plug 451 is fixed to the side of the first support frame 41, and the seal box 100 is provided with a power supply plug, when the plug 451 is connected with the power supply plug, the power is supplied to the forming cylinder 30.

Furthermore, after the powder is poured, the powder needs to be screened to distinguish the printing powder from the filling powder, wherein the printing powder and the filling powder have different particle sizes, the particle size of the filling powder is larger than that of the printing powder, the filling powder is used as a non-consumable product and can be recycled, the required volume of the filling powder is determined according to the size of a workpiece, the printing powder is used as a consumable, and the preparation amount is larger than the volume of the product.

As shown in fig. 2 and fig. 4 to 5, the sieve plate 51 is arranged obliquely to the horizontal plane, the second powder discharge port 511 is located at a low position of the sieve plate 51, a collecting hopper 513 is arranged below the sieve plate 51, and the first powder discharge port 512 is arranged at the bottom of the collecting hopper 513.

When the powder is poured onto the sieve plate 51, the powder larger than the sieve opening of the sieve plate 51 is left on the surface of the sieve plate 51, and the powder smaller than the sieve opening of the sieve plate 51 falls into the collecting hopper 513, so that the powder larger than the sieve opening of the sieve plate 51 is separated from the first powder discharge port 512 and the powder smaller than the sieve opening of the sieve plate 51 is separated from the second powder discharge port 511.

In the preferred embodiment, a vibrating motor is provided on the sieve plate 51, and the powder on the sieve plate 51 is sufficiently separated by the vibrating action of the vibrating motor.

Further, the first powder discharging port 512 and the second powder discharging port 511 are both provided with valves, and the valves are used for controlling the on-off of the first powder discharging port 512 or the second powder discharging port 511. That is, when the powder is sieved, the valve is closed, and when the powder sieving is completed, the valve is opened, so that the filling powder is discharged from the second powder discharge port 511, and the printing powder is discharged from the first powder discharge port 512.

Optionally, the first powder discharge port 512 is connected to a first powder receiving cylinder 57, and the second powder discharge port 511 is connected to a second powder receiving cylinder 58, where the first powder receiving cylinder 57 is used for supplying powder to the printing powder bin 52, and the second powder receiving cylinder 58 is used for supplying powder to the filling powder bin 53.

In a further alternative embodiment, a first powder suction pipeline 501 is arranged between the first powder receiving cylinder 57 and the printing powder bin 52, a first powder suction device 54 is arranged on the first powder suction pipeline, and the first powder suction device 54 is used for sucking the printing powder in the first powder receiving cylinder 57 into the printing powder bin 52; a second powder suction pipeline is arranged between the second powder receiving cylinder 58 and the filling powder bin 53, a second powder suction device 55 is arranged on the second powder suction pipeline, and the second powder suction device 55 is used for sucking the filling powder in the second powder receiving cylinder 58 into the filling powder bin 53.

In this way, the powder in the powder receiving cylinder is recovered into the distributing bin by using a powder sucking device for sucking.

First mode of powder suction

In an alternative embodiment, as shown in fig. 7 and 8, each of the first powder receiving cylinder 57 and the second powder receiving cylinder 58 includes a transition bin 521 and a powder supply bin 522, the transition bin 521 is located above the powder supply bin 522, an isolation valve 523 is disposed between the transition bin 521 and the powder supply bin 522, and a purge valve is disposed on the transition bin 521 and used for purging the transition bin 521, so that the transition bin 521 and the powder supply bin 522 have the same atmosphere environment.

Specifically, the printing powder of the first powder receiving cylinder 57 is sucked by the first powder sucker 54 and discharged into the transition bin 521 of the printing powder bin 52, wherein the gas sucked by the first powder sucker 54 is discharged out of the seal box 100, and since the printing powder sucked into the transition bin 521 contains air, which is different from the atmosphere in the seal box 100, the transition bin 521 needs to be first purged.

In a specific embodiment, the purge valve is a three-way valve, wherein the first end is connected to the transition bin 521, the second end is connected to the vacuum pumping device, and the third end is connected to the shielding gas charging device, and in the first step, the first end and the second end are kept to be communicated for vacuum pumping, the first end and the third end are kept to be communicated, and the inert gas is charged, so that the atmosphere environment of the transition bin 521 is the same as that of the powder supply bin 522.

Wherein, the steps of the recovery and the gas washing of the powder filling cabin are the same as those of the printing powder cabin.

Second mode of powder suction

Further, in the preferred embodiment, the exhaust end of the powder sucker is directly introduced into the sealed box 100 through the exhaust duct 503, and the wind equalizing box 504 is arranged to avoid causing large disturbance of the internal wind field.

Specifically, the powder suction device comprises a powder collection box, a powder suction inlet 541, a powder outlet 543 and an air flow outlet 542, a powder collection cavity 540 is arranged in the powder collection box, a first end of the powder suction inlet 541 is connected with a powder suction pipeline, a second end of the powder suction inlet is connected with the powder collection cavity 540, the powder outlet 543 is located at the bottom of the powder collection cavity 540, a first end of the air flow outlet 542 is connected to the upper portion of the powder collection cavity 540, and a second end of the air flow outlet 542 is connected into the seal box 100.

Thus, when the mixture of the gas flow and the powder enters from the powder suction inlet 541, the powder falls into the powder collection chamber 540 by the downward guiding action of the guide pipe 544, and the negative pressure end (gas flow outlet 542) sucks the gas out, and since the space of the powder collection chamber 540 is large, the powder cannot be sucked out simultaneously, and therefore, the powder is collected at the powder outlet 543 and discharged into the corresponding powder bin through the powder discharge pipe 502.

Further, the gas flows from the gas flow cylinder to 545 to the gas flow outlet 542 in the powder collection chamber 540, flows out from the gas flow outlet 542, and is introduced into the sealing box 100 from the air exhaust pipe 503, so that the gas in the sealing box 100 circulates without damaging the atmosphere of the sealing box 100.

Wherein, the powder suction device is an air suction device capable of forming negative pressure at the airflow outlet 542.

In conjunction with the above embodiment, the printing powder hopper 52 and the filling powder hopper 53 maintain a continuous amount of powder by pouring the molding cylinder 30-sieving the powder-sucking the recovered powder to achieve a small amount of printing powder to complete the printing of the entire workpiece.

Referring to fig. 8, one powder scraping method in this embodiment is as follows: the scraper member 61 includes a first scraper blade 61a and a two-way valve 62, the first scraper blade 61a is connected to the powder supply bin 522 through a powder conveying pipe, and the two-way valve 62 is provided between the first scraper blade 61a and the powder conveying pipe, the two-way valve 62 is a three-way valve, the first end is connected to the powder conveying pipe, the second end is located at the left side of the first scraper blade 61a, the third end is located at the right side of the first scraper blade 61a, and the two-way valve 62 is configured to be interlocked with the first scraper blade 61 a.

Specifically, when the first doctor blade 61a is located on the left side of the forming cylinder and moves from the left side to the right side, the first end and the third end of the two-way valve 62 are conducted, the powder falls on the right side of the first doctor blade 61a, the first doctor blade 61a scrapes the falling powder on the upper end surface 311 of the forming cylinder 30 from left to right, when the first doctor blade 61a is located on the right side of the forming cylinder and moves from the right side to the left side, the first end and the second end of the two-way valve 62 are conducted, the powder falls on the left side of the first doctor blade 61a, and the first doctor blade 61a scrapes the falling powder on the upper end surface 311 of the forming cylinder 30 from right to left.

The powder scraping mode of the filling powder is the same as that of the printing powder.

When the powder-laying amount of the filling powder at one time is large, the powder-laying is not required to be reciprocated, and preferably, a sufficient amount of powder can be directly dropped on the upper end surface 311 of the forming cylinder 30 and scraped into the formed concave pit between the base plate 32 and the cylinder body of the forming cylinder at one time by a scraper to increase the powder-laying speed of the filling powder.

Further, as shown in fig. 3, a baffle 62 is provided outside the doctor blade 61 to prevent the powder from spilling out of the molding cylinder.

It will be appreciated that the doctor blade 61 and the shutter 62 are connected to a lifting mechanism (not shown in the drawings) and that the doctor blade 61 and the shutter 62 are lifted up when the molding cylinder 30 is turned upside down to avoid interference with the movement of the molding cylinder 30.

In the above embodiment, in order to ensure that the powder does not fall onto the positioning machine, a guide plate 514 is disposed on one side of the forming cylinder 30, a first end of the guide plate 514 is abutted against the edge of the forming cylinder 30, a second end of the guide plate 514 is located above the screen 51, and the excessive powder on the forming cylinder 30 can be scraped to the guide plate 514 by the doctor blade 61 and then slides to the screen 51 along with the guide plate 514.

[ powder supply method for additive processing ]

The second aspect of the invention provides a technical scheme, and the powder supply method for additive machining comprises the following steps:

step 1, defining the prepared printing powder amount as Q, the powder filling amount as E, the maximum volume of the forming cylinder 30 as W, wherein Q is smaller than W, Q + E > W, the volume change of the forming cylinder 30 is W1 every time the additive height H1, overturning the forming cylinder 30, and pouring the powder in the forming cylinder 30 to a powder sieving component, wherein Q is smaller than W1;

step 2, collecting the printing powder screened by the powder screening component 50, refilling the printing powder into the printing powder bin 52, collecting the filling powder screened by the powder screening component 50, and filling the filling powder into the filling powder bin 53;

step 3, backfilling the filling powder in the filling powder bin 53 into the forming cylinder 30, wherein the backfilled filling powder is smaller than W1;

and 4, continuously increasing the materials by using the printing powder recovered from the printing powder bin 52, and repeating the steps 1-3 until the printing is finished.

Aiming at the processing mode of layer-by-layer sintering forming of powder spreading printing, the invention aims to reduce the total usage amount of printing powder by combining the steps, and gradually and completely sintering the printing powder to form a workpiece body by pouring the powder in the forming cylinder for multiple times and recycling the printing powder and refilling the filling powder in a mode of recovering the printing powder and filling the filling powder, thereby reducing the usage amount of the printing powder and keeping continuous powder supply in the printing process.

Preferably, in step 2, refilling the printing powder into the printing powder hopper 52 comprises the following method:

the method a comprises the steps of collecting printing powder and filling powder which are screened by a powder screening component 50 by using a powder receiving cylinder, recovering the printing powder collected in the powder receiving cylinder to a printing powder bin 52 in a suction mode, and recovering the filling powder collected in the powder receiving cylinder to a filling powder bin 53;

and b, collecting the printing powder and the filling powder which are screened by the powder screening component 50 by using a powder receiving cylinder, recovering the printing powder collected in the powder receiving cylinder to a printing powder bin 52 by using a mechanical lifting conveying mode, and recovering the filling powder collected in the powder receiving cylinder to a filling powder bin 53.

Alternatively, the mechanical lifting transportation comprises lifting the powder to a predetermined height in a closed cylinder by means of auger transportation.

Preferably, in the method a, the air flow of the air exhaust is discharged out of the sealing box 100, the powder receiving cylinder comprises a transition bin and a powder supply bin, when the powder is sucked into the transition bin from the powder receiving cylinder, the transition bin and the powder supply bin are in an isolation state, after the suction action is stopped, the transition bin is subjected to air washing, the transition bin and the powder supply bin are enabled to have the same atmosphere environment, then the transition bin and the powder supply bin are communicated, and the powder in the transition bin enters the powder supply bin.

In a specific embodiment, the first powder discharge port 511 and the second powder discharge port 512 are respectively provided with a powder receiving cylinder, a first powder receiving cylinder 57 and a second powder receiving cylinder 58, and when the powder in the powder receiving cylinders is full, the powder is sucked into the corresponding bin in a powder sucking manner by a powder sucking device.

When the powder is added into the corresponding storage bin, the isolating valve 523 is closed, the bin cover is opened, the powder is added into the transition storage bin 521, the bin cover is closed after the powder is filled, the first end and the second end of the air washing valve are kept to be communicated, vacuumizing is carried out, the first end and the third end of the air washing valve are kept to be communicated again, and inert gas is filled, so that the atmosphere environment of the transition storage bin 521 is the same as that of the powder supply storage bin 522, at the moment, the isolating valve 523 can be opened, and the powder of the transition storage bin 521 falls into the powder supply storage bin 522.

In combination with the above embodiment, the printing powder in the forming cylinder is poured during printing, and is recycled and added into the printing powder bin through screening, in the process, the filling powder in the filling bin is used for refilling to a preset height, so that the printing powder is always positioned in a height layer near a printing layer, and in the process of powder sintering, the continuous powder supply of the printing powder is kept, and meanwhile, the total consumption of the printing powder is reduced, so that the processing cost is saved.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (12)

1. A powder supply device for additive manufacturing, comprising:

a printing powder bin (52) for containing printing powder;

a filling powder bin (53) for containing filling powder;

the powder screening component (50) comprises a screen plate (51), a first powder discharge port (512) positioned at the lower layer of the screen plate (51) and a second powder discharge port (511) positioned at the upper layer of the screen plate (51);

a forming cylinder (30) arranged above the powder sieving component;

the scraper component (61) is used for scraping printing powder in the printing powder bin (52) and filling powder in the filling powder bin (53) to the surface of the forming cylinder (30) to smooth the powder;

the position changing machine (40) is arranged at the bottom of the forming cylinder (30) and can drive the forming cylinder (30) to overturn, so that powder in the forming cylinder (30) is poured to the powder screening component (50), the powder screening component (50) screens printing powder to the first powder discharge port (512), and filled powder is screened to the second powder discharge port (511);

a first powder receiving cylinder (57) connected to the first powder discharge port (512);

a second powder receiving cylinder (58) connected to the second powder discharge port (511);

the powder screening component, the forming cylinder (30), the scraper component (61) and the positioner (40) are arranged in a sealing box (100), inert protective gas is arranged in the sealing box (100), the first powder receiving cylinder (57) is used for supplying powder to the printing powder bin (52), and the second powder receiving cylinder (58) is used for supplying powder to the filling powder bin (53).

2. The powder supply device for additive manufacturing according to claim 1, wherein the sieve plate (51) is arranged obliquely to a horizontal plane, the second powder discharge port (511) is located at a low position of the sieve plate (51), a collecting hopper is arranged below the sieve plate (51), and the first powder discharge port (512) is arranged at the bottom of the collecting hopper.

3. The powder supply device for additive manufacturing according to claim 2, wherein a vibration motor is provided on the sieve plate (51).

4. The powder supply device for additive manufacturing according to claim 1, wherein the first powder discharge port (512) and the second powder discharge port (511) are provided with valves, and the valves are used for controlling the on-off of the first powder discharge port (512) or the second powder discharge port (511).

5. The powder supply device for additive manufacturing according to claim 1, wherein a first powder suction pipeline is arranged between the first powder receiving cylinder (57) and the printing powder bin (52), a first powder sucker (54) is arranged on the first powder suction pipeline, and the first powder sucker (54) is used for sucking printing powder in the first powder receiving cylinder (57) into the printing powder bin (52); and a second powder pumping pipeline is arranged between the second powder receiving cylinder (58) and the filling powder bin (53), a second powder sucking device (55) is arranged on the second powder pumping pipeline, and the second powder sucking device (55) is used for sucking the filling powder in the second powder receiving cylinder (58) into the filling powder bin (53).

6. The powder supply device for additive processing according to claim 5, wherein each of the first powder receiving cylinder (57) and the second powder receiving cylinder (58) comprises a transition bin (521) and a powder supply bin (522), the transition bin (521) is located above the powder supply bin (522), an isolation valve is arranged between the transition bin and the powder supply bin, and a purge valve is arranged on the transition bin and used for ventilating the transition bin to enable the transition bin and the powder supply bin to have the same atmosphere environment.

7. The powder supply device for additive manufacturing according to claim 5, wherein the powder collector comprises a powder collection box, a powder collection inlet (541), a powder outlet (543) and an air flow outlet (542), a powder collection chamber (540) is arranged in the powder collection box, a first end of the powder collection inlet (541) is connected with a powder suction pipeline, a second end of the powder collection inlet is connected with the powder collection chamber (540), the powder outlet (543) is located at the bottom of the powder collection chamber (540), a first end of the air flow outlet (542) is connected to the upper portion of the powder collection chamber (540), and a second end of the air flow outlet (542) is connected into the sealed box (100).

8. The powder supply device for additive manufacturing according to claim 1, wherein the positioner (40) includes a first support frame (41) and a second support frame (42), the second support frame (42) is disposed inside the first support frame (41) and can be driven by a turning drive to turn in a Y-axis direction with respect to the first support frame (41), and the forming cylinder (30) is connected to the second support frame (42) to turn the forming cylinder (30) in the Y-axis direction.

9. The powder supply device for additive manufacturing according to claim 1, wherein the forming cylinder (30) and the second support frame (42) are detachably connected.

10. A powder supply method for additive machining is characterized by comprising the following steps:

step 1, defining the amount of prepared printing powder as Q, the amount of filling powder as E, and the maximum volume of a forming cylinder (30) as W, wherein Q is less than W, Q + E > W, and turning over the forming cylinder (30) to pour the powder in the forming cylinder (30) to a powder screening part every time when the additive height H1 is achieved (the volume change of the forming cylinder (30) is W1), wherein Q is less than W1;

step 2, collecting the printing powder screened by the powder screening component (50), refilling the printing powder into the printing powder bin (52), collecting the filling powder screened by the powder screening component (50), and filling the filling powder into the filling powder bin (53);

step 3, backfilling the filling powder in the filling powder bin (53) into the forming cylinder (30), wherein the backfilled filling powder is smaller than W1;

and 4, continuously increasing the material by using the printing powder recovered in the printing powder bin (52), and repeating the steps 1-3 until the printing is finished.

11. The powder supply method for additive manufacturing according to claim 10, wherein refilling of printing powder into a printing powder bin (52) in step 2 comprises the following method:

the method comprises the steps that a powder receiving cylinder is used for collecting printing powder and filling powder which are screened by a powder screening component (50), the printing powder collected in the powder receiving cylinder is recovered to a printing powder bin (52) in a suction mode, and the filling powder collected in the powder receiving cylinder is recovered to a filling powder bin (53);

and b, collecting the printing powder and the filling powder which are screened by the powder screening component (50) by using a powder receiving cylinder, recovering the printing powder collected in the powder receiving cylinder to a printing powder bin (52) by using a mechanical lifting conveying mode, and recovering the filling powder collected in the powder receiving cylinder to a filling powder bin (53).

12. The powder supplying method for additive manufacturing according to claim 11, wherein in method a, the air flow of the air exhaust is exhausted to the outside of the sealing box (100), the powder receiving cylinder comprises a transition bin and a powder supplying bin, when the powder is sucked from the powder receiving cylinder to the transition bin, the transition bin and the powder supplying bin are in an isolated state, after the suction action is stopped, the transition bin is subjected to air washing to enable the transition bin and the powder supplying bin to have the same atmosphere environment, then the transition bin and the powder supplying bin are communicated, and the powder in the transition bin enters the powder supplying bin.

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