WO2024183708A1

WO2024183708A1 - Bidirectional powder spreading apparatus and method based on single powder compartment, and 3d printing device

Info

Publication number: WO2024183708A1
Application number: PCT/CN2024/080004
Authority: WO
Inventors: 沈李耀威
Original assignee: 云耀深维(江苏)科技有限公司
Priority date: 2023-03-06
Filing date: 2024-03-04
Publication date: 2024-09-12
Also published as: CN116275136A

Abstract

A bidirectional powder spreading apparatus (10) and method based on a single powder compartment, and a 3D printing device. The apparatus comprises: a powder compartment (11) capable of promoting a part of powder to overflow under the action of a powder supply lifting/lowering apparatus (111); a powder spreading unit (12) for conveying the overflowed powder in a direction away from the powder compartment (11); a forming compartment (13) consisting of a powder storage unit (14) and a forming platform (15) arranged in the middle of the powder storage unit (14), wherein the powder spreading unit (12) can convey powder to the forming platform through the side of the powder storage unit (14) close to the powder compartment (11) in a powder spreading direction (15) and continuously conveys a part of the powder to the side of the powder storage unit (14) distant from the powder compartment (11), and reversely conveys the powder formed on the side of the powder storage unit (14) distant from the powder compartment (11) to the forming platform (15) in an opposite direction of the powder spreading direction. The powder spreading device (10) achieves bidirectional powder spreading under the condition of a single powder compartment (11), and further reduces the distance of reverse powder spreading, thereby improving the powder spreading efficiency.

Description

Bidirectional powder spreading device, method and 3D printing equipment based on single powder bin

This application claims priority to patent application 202310206157.9 filed with the China Patent Office on March 6, 2023, the entire contents of which are incorporated by reference into this application.

Technical Field

The present invention relates to the field of 3D printing, and in particular to a two-way powder spreading device and method based on a single powder bin, and a 3D printing device.

Background Art

When building parts through 3D printing, the parts are often planed into several two-dimensional plane structures, and then printed layer by layer to finally form the parts. Especially for the powder sintering/melting technology, a layer of metal powder/non-metal powder is laid layer by layer, and then the laid layer of metal powder is selectively sintered/melted through a heat source (usually a laser) to construct the structure of the part in that layer, and the part is finally built by laying powder layer by layer and then sintering/melting.

In the current field of powder-laying 3D printing technology, powder-laying time is a key factor affecting printing efficiency. How to improve powder-laying efficiency economically and efficiently is one of the important research contents in the field of 3D printing.

In order to improve the powder spreading efficiency, two powder bins are usually set up for bidirectional powder spreading in the prior art. Although the design of the double powder bin structure improves the powder spreading efficiency, the two powder bins increase the moving distance of the scraper, and the two powder bins greatly increase the complexity of the powder bin structure, which has limited improvement on the powder spreading efficiency and greatly increases the cost of the equipment.

Summary of the invention

In order to achieve bidirectional powder spreading within a short distance to improve the powder spreading efficiency, one aspect of the present invention provides a powder spreading device, including: a powder bin for storing powder for 3D printing; wherein the powder bin can cause a part of the powder to overflow from the powder bin under the action of a powder supply lifting device; a powder spreading part, used to convey the powder overflowing from the powder bin in a direction away from the powder bin; a forming bin, wherein the forming bin is composed of a powder storage part and a forming platform arranged in the middle of the powder storage part; at least a part of the powder is pre-stored in the powder storage part to form a first powder bed tending to a fixed form, and at least a part of the powder is conveyed layer by layer by the powder spreading part to the top of the forming platform to form a second powder bed for forming parts; wherein the powder spreading part is configured to convey the powder to the forming platform through the powder storage part close to the side of the powder bin in one powder spreading direction, and continuously convey a part of the powder to the powder storage part away from the side of the powder bin, and reversely convey the powder formed on the powder storage part away from the side of the powder bin to the forming platform along the opposite direction of the powder spreading direction.

Preferably, the forming platform is arranged to be driven to descend along the middle of the powder storage portion in response to the forming of any layer of parts in the second powder bed.

Preferably, the forming platform can be driven by a forming lifting device to rise or fall along the middle of the powder storage part.

Preferably, the powder spreading section transports the powder between the powder storage section and the forming platform back and forth in a cycle until the powder is completely consumed, and then re-transports the powder newly overflowed from the powder bin.

Preferably, the powder spreading part can be moved parallel to the powder spreading direction and lifted and lowered perpendicular to the powder spreading direction under the drive of a translation lifting device.

Preferably, an inclined platform is provided on a side of the powder storage portion away from the powder bin, so that the powder transported to the corresponding area on this side forms an accumulation area on one side of the inclined platform.

Preferably, the translation and lifting device is configured to drive the powder spreading part to rise to a height at least greater than the highest point of the stacking area when the powder spreading part moves to the side of the stacking area close to the powder bin, and continuously drive the powder spreading part to move at the current height to the side of the stacking area away from the powder bin, and continuously drive the powder spreading part to descend to the original height.

Preferably, it also includes a vibration device capable of driving the inclined platform to vibrate.

Preferably, the vibration device is arranged on the other side of the inclined platform and/or arranged inside the inclined platform.

Preferably, a heating device is provided inside the inclined platform.

Preferably, the powder spreading part is a scraper.

Preferably, the scraper is composed of a main scraper and auxiliary scrapers respectively arranged on both sides of the main scraper.

Preferably, when the scraper acts on the forming platform, the main scraper is used to spread powder on the forming platform.

Preferably, the auxiliary scraper is spaced apart from the main scraper to form a powder retaining dam between the main scraper and the auxiliary scraper to prevent the powder on the forming platform from deviating outwards.

Preferably, the height of the main scraper relative to the auxiliary scraper is adjustable.

Preferably, the scraper tool has a main body, and the auxiliary scraper is fixed below the main body; a cavity is provided in the main body, and electric telescopic rods are respectively provided at both ends of the top wall of the cavity, and one end of the electric telescopic rod is connected to the main scraper, which is used to drive the main scraper to move in the Z-axis direction to adjust the height of the main scraper relative to the auxiliary scraper.

In order to achieve bidirectional powder spreading within a short distance to improve the powder spreading efficiency, one aspect of the present invention provides a 3D printing device, which includes a structure in which the aforementioned powder spreading device is installed on the 3D printing device.

In order to achieve bidirectional powder spreading within a short distance to improve the powder spreading efficiency, one aspect of the present invention provides a powder spreading method, which is applied to a structure that at least includes the powder spreading device described above, and the method includes: driving the powder spreading part in the powder spreading direction to convey the powder overflowing from the powder bin through the powder storage part on the side close to the powder bin to the top of the forming platform for powder laying of formed parts; continuously driving the powder spreading part in the powder spreading direction to convey a part of the powder to the powder storage part on the side away from the powder bin; and reversely conveying the powder formed on the powder storage part on the side away from the powder bin to the forming platform for laying in the opposite direction of the powder spreading direction.

One aspect of the present invention also provides a powder spreading method, which is applied to a structure that includes at least the powder spreading device described above, and the method includes: continuously driving the powder spreading part in the powder spreading direction to transport the powder to the stacking area on the side of the inclined platform away from the powder bin; controlling the vibration device to start to drive the inclined platform to vibrate; driving the powder spreading part to rise to a height at least greater than the highest point of the stacking area, and continuously driving the powder spreading part to move at the current height to the side of the stacking area away from the powder bin, and continuously driving the powder spreading part down to the original height; and reversely transporting the powder formed on the side of the inclined platform away from the powder bin to the forming platform in the opposite direction of the powder spreading direction.

The powder spreading device of the present application realizes bidirectional powder spreading in the case of a single powder bin, and at the same time, further reduces the distance of reverse powder spreading, improves the efficiency of powder spreading, and greatly reduces the mechanical structure of multiple powder bins.

The present application designs an optimized scraper structure, which can avoid the appearance of a trapezoidal powder spreading structure during the powder spreading process and achieve a more precise powder spreading morphology.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram showing the structure of a powder spreading device provided by one embodiment of the present invention;

FIG2 is a schematic diagram showing the structure of a powder spreading device provided by one embodiment of the present invention;

FIG3 is a schematic diagram showing the structure of a forming bin provided by one embodiment of the present invention;

FIG4 is a schematic diagram showing a lifting/translation process of a powder spreading part according to one embodiment of the present invention;

FIG5 is a schematic diagram showing a cross-sectional view of a powder bed provided by one embodiment of the present invention;

FIG6 is a schematic diagram showing a cross-sectional view of a powder bed under a trapezoidal powder spreading structure provided in one embodiment of the present invention;

FIG7 is a schematic diagram showing the structure of a scraper provided in one embodiment of the present invention;

FIG8 is a schematic diagram showing a cross-sectional view of a powder bed under a powder spreading structure provided in one embodiment of the present invention;

FIG9 is a schematic diagram showing a process of a powder spreading method provided by one embodiment of the present invention;

FIG10 is a schematic diagram showing a process of a powder spreading method provided in yet another embodiment of the present invention;

FIG11 is a schematic diagram showing the structure of a scraper provided in one embodiment of the present invention;

FIG. 12 is a schematic diagram showing the connection of an electric telescopic rod provided in one embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

According to one aspect of the present invention, the powder spreading device is used in a 3D printing device, that is, it can be used as a part of the structure of the 3D printing device. The 3D printing device described here is preferably a 3D printing type that uses a laser beam/electron beam as an energy source, such as selective laser sintering (SLS), selective laser melting (SLM), etc. Powder bed-based 3D printing technology requires that the powder be spread in advance, and the material is melted by laser scanning to solidify the loose powder together. The powder is spread layer by layer through scanning, and the retractable platform sinks to finally obtain a solid body wrapped by powder.

The 3D printing device is composed of at least several parts such as a mechanical unit, an optical path unit and a computer control system. The powder spreading device of the present invention is preferably used as a part of the mechanical unit, and of course it can be used alone as a part parallel to the mechanical unit, the optical path unit and the computer control system. In the specific spatial arrangement form, the optical path unit can be arranged above the mechanical unit, and can also be arranged based on the core invention points taught in this application according to the actual structural design. In the control logic, the control of the mechanical unit and the optical path unit is realized by the computer control system, that is, the control of the powder spreading device of the present invention is preferably realized by the computer control system.

The mechanical unit of 3D printing equipment is usually composed of a powder bin, a forming bin, a powder supply lifting device, a forming lifting device, and a powder spreading scraper. This single powder bin setting form can usually only achieve one-way powder spreading. If two-way powder spreading is to be achieved, it is necessary to add a powder bin on the other side of the forming bin. Although the double powder bin structure improves the efficiency of powder spreading, the two powder bins increase the distance the scraper moves, and the two powder bin structures greatly increase the complexity of the powder bin structure, which has limited improvement in powder spreading efficiency and greatly increases the cost of the equipment.

To this end, the present invention provides a bidirectional powder spreading device based on a single powder bin, that is, bidirectional spreading of powder is achieved under the setting form of a single powder bin structure.

As shown in FIG. 1 , in some embodiments, the powder spreading device 10 of the present invention is composed of components such as a powder bin 11 , a powder supply lifting device 111 , a powder spreading portion 12 , a forming bin 13 , and a forming lifting device 131 .

The powder bin 11 is arranged on one side of the forming bin 13 and is used to store powder for 3D printing. The lifting and lowering of the powder bin 11 is driven by a powder supply lifting device 111, that is, the powder bin 11 is driven to rise by the powder supply lifting device 111, thereby causing a part of the powder in the powder bin 11 to overflow from the powder bin 11.

The specific form of the powder spreading part 12 can be one of a powder spreading brush, a powder spreading roller and a scraper, and the present invention is preferably a scraper. The powder spreading part 12 is movably arranged above the powder bin 11 and the forming bin 13, so that it can circulate above the powder bin 11 and the forming bin 13. When the powder spreading part 12 moves from above the powder bin 11 to above the forming bin 13, the powder overflowing from the powder bin 11 can be transported in a direction away from the powder bin 11, that is, the powder can be transported to the top of the forming bin 13.

The powder described here refers to the material to be processed, which is used in a powder state. For example, the powder can be mainly composed of a material made of metal or polymer. During the construction process of the formed part, the powder is laid layer by layer on the top of the forming bin 13, and then a powder bed 16 is formed in the forming bin 13.

The forming bin 13 is composed of a powder storage part 14 and a forming platform 15. As shown in FIG3 , the powder storage part 14 is a bin body with an open top surface, which can store powder in advance to form a first powder bed 161 tending to a fixed shape; the pre-storage described here means that the powder storage in the powder storage part 14 has been completed before the powder is spread on the forming platform 15, and the source of the powder in the powder storage part 14 can be the powder overflowed from the powder bin 11 transported by the powder spreading part 12, or the powder can be introduced into the powder storage part 14 at one time and quickly by using an additional powder supply device to fill its internal space, so that after the powder is stored, the powder layer at the top and the top surface of the powder storage part 14 tend to be on the same horizontal plane. The forming platform 15 is arranged in the middle of the powder storage part 14 and can be lifted and lowered along the middle of the powder storage part 14, which can be regarded as having a channel in the middle of the powder storage part 14, and the forming platform 15 is arranged in the channel and can be lifted and lowered along the inner wall of the channel under the action of external force.

In some embodiments, the upper part of the forming platform 15 is used to provide a manufacturing site for the formed parts, that is, the formed parts are finally constructed above the forming platform 15; the distance that the forming platform 15 descends each time is the layer thickness; after the formed parts are constructed, the forming platform 15 rises to facilitate the removal of the constructed formed parts and prepare for the next construction. The lifting and lowering of the forming platform 15 is driven by the forming lifting device 131, that is, the forming platform 15 can be lifted and lowered in the middle of the powder storage part 14 under the drive of the forming lifting device 131. The powder spreading part 12 forms a second powder bed 162 for forming parts by conveying the powder overflowing from the powder bin 11 to the upper part of the forming platform 15 layer by layer; after completing the powder spreading of any layer above the forming platform 15, the tops of the first powder bed 161 and the second powder bed 162 tend to be in the same horizontal plane, and the "tend to" described here means close rather than the same. The forming platform 15 can respond to the forming of any layer of parts in the second powder bed 162 and descend along the middle of the powder storage section 14 driven by the forming lifting device 131. That is, whenever the forming of the top layer of powder in the second powder bed 162 is completed, the forming lifting device 131 will be triggered to drive the forming platform 15 to descend one layer to facilitate the laying of the next layer of powder.

The combination of the first powder bed 161 and the second powder bed 162 constitutes the powder bed 16, and the area corresponding to the first powder bed 161 is named the first area 161, and the area corresponding to the second powder bed 162 is named the second area 162. It can be seen that the cross section of the powder storage portion 14 completely covers the cross section of the forming platform 15, so as to separate the first area 161 from at least two sides of the second area 162, as shown in FIG5, the first area 161 separated on the left side of the second area 162, that is, the left side of the first area is 161a, the first area 161 separated on the right side of the second area 162, that is, the right side of the first area is 161b, and the first area 161 separated on the upper side of the second area 162, that is, the upper side of the first area is 161c, and the first area 161 separated on the lower side of the second area 162, that is, the lower side of the first area is 161d.

It should be understood that the second area 162 corresponds to the area of the forming platform 15, that is, the manufacturing area of the formed part, and the first area 161 corresponds to the remaining area after the forming platform 15 area is removed.

In the present application, the powder spreading section 12 is configured to be able to convey the powder to the forming platform 15 through the powder storage section 14 on the side close to the powder bin in one powder spreading direction, and to continuously convey a portion of the powder to the powder storage section 14 on the side away from the powder bin 11, and to reversely convey the powder formed on the powder storage section 14 on the side away from the powder bin to the forming platform 15 in the opposite direction of the powder spreading direction. That is, the powder needs to pass above the powder storage section 14 before being conveyed to the forming platform 15, and since the powder storage section 14 itself stores powder that is almost flush with the powder spreading plane of the powder spreading section 14, the powder conveyed to the forming platform 15 will not be consumed by the powder storage section 14 when passing through the powder storage section 14, so that more powder can be conveyed to the forming platform 15 and the powder storage section 14 on the side away from the powder bin 11, so as to create more powder sources for subsequent reverse powder spreading. And by making the non-part forming area in the forming chamber 13 (i.e., the first zone 161/first powder bed 161) have a thicker powder layer, these thicker powder layers can better reflect the powder spreading conditions of the scraper when the scraper passes by, so as to facilitate subsequent powder spreading adjustments.

As shown in Figure 5, when solid impurities appear in the first area 161, the thicker powder layer in the first area 161 can better hide the impurities, thereby better protecting the scraper, and the thicker powder layer can better protect the formed parts in the second area 162 and prevent the solid impurities from affecting the parts under the action of the scraper.

The powder spreading process in one embodiment of the present application is described in detail below in conjunction with FIG1. When the printing of the current layer of the formed part is completed (based on the optical path unit), the forming platform 15 moves downward by a preset height (layer thickness) driven by the forming lifting device 131, and the powder bin 11 moves upward by a preset height driven by the powder supply lifting device 111, so as to cause a part of the powder in the powder bin 11 to overflow from the powder bin 11; the layer thickness laid on the forming platform 15 is the thickness Δd between the lowest point of the powder spreading part 12 (scraper) and the powder layer of the forming platform 15; the scraper moves to the right to first convey the powder overflowing from the powder bin 11 To the left side 161a of the first zone; then the scraper continues to move to the right to transport the powder to the second zone 162 (forming platform 15/part forming area) to lay the powder in this area; then the scraper continues to move to the right to transport the remaining powder to the right side 161b of the first zone; when the scraper moves to the area on the right side 161b of the first zone, it moves in the opposite direction, that is, to the left (the movement process is opposite to the previous stroke), so as to transport the excess powder in the opposite direction to the forming platform 15 for re-powdering, thereby achieving two-way powder laying. If there is still excess powder, the scraper continues to move to the right to transport the excess powder to the right side 161b of the first zone, and the cycle repeats until all the powder is consumed. When the scraper transports the powder between the powder storage part 14 and the forming platform 15 in a cycle until it is completely consumed, the powder newly overflowed from the powder bin 11 is re-transported.

Referring to Figure 2, in some embodiments, the powder spreading device 10 of the present invention is composed of components such as a powder bin 11, a powder supply lifting device 111, a powder spreading part 12, a forming bin 13, a forming lifting device 131, an inclined platform 18 and a vibration device 19.

The inclined platform 18 is arranged on the side of the first zone 161 away from the powder bin, that is, the side of the powder storage part 14 away from the powder bin 11, specifically on the right side of the right side 161b of the first zone, which can form an accumulation area 17 on the left side of the inclined platform 18 with the powder transported to the corresponding area on this side.

In one embodiment, the vibration device 19 is disposed on the right side of the inclined platform 18; in another embodiment, the vibration device 19 can also be disposed inside the inclined platform 18; the vibration device 19 is used to drive the inclined platform 18 to vibrate at a certain frequency.

After the scraper completes the powder conveying in the area 161b on the right side of the first zone, the excess unlaid powder will be accumulated on the right side of the first zone 161b. Under the action of the scraper, the excess powder will be accumulated on the inclined platform 18. By driving the vibration device 19 to start and vibrate at a preset vibration frequency, under the action of the vibration device 19, the inclined platform 18 vibrates rapidly, so that the excess unlaid powder can be quickly accumulated on the left side of the scraper, and an accumulation area 17 as shown in Figure 2 is formed on the left side of the scraper; when the scraper moves in the opposite direction to the left, the powder in the accumulation area 17 can be spread again, thereby realizing two-way powder spreading.

In some embodiments, a heating device may be further provided inside the inclined platform 18 to preheat the powder accumulated on the inclined platform 18 , which is beneficial to the dispersion of the powder and reduces the clustering phenomenon.

In some embodiments, the powder spreading part 12 can be moved parallel to the powder spreading direction and lifted and lowered perpendicular to the powder spreading direction under the drive of a translation lifting device (not shown). The translation lifting device is configured to drive the powder spreading part 12 to rise to a height at least greater than the highest point of the stacking area when the powder spreading part 12 moves to the side of the stacking area close to the powder bin 11, and continuously drive the powder spreading part 12 to move at the current height to the side of the stacking area away from the powder bin 11, and continuously drive the powder spreading part 12 to descend to the original height.

As shown in reference figure 4, when the scraper moves to the left side of the stacking area, that is, at location 1, the translation and lifting device controls the scraper to rise to location 2, and randomly continues to control the scraper to move right to location 3, and finally controls the scraper to descend to location 4, that is, the original height, thereby completing the control process of the scraper moving from the left side to the right side of the stacking area.

During the powder spreading process, the powder is often spread larger than the area of the forming platform 15 to ensure a sufficient forming area. However, in the actual powder spreading process, as shown in FIG6 , as the scraper moves to the right, as the powder is consumed, during the movement of the scraper, the area that can actually be laid is a trapezoidal structure. This trapezoidal structure is difficult to achieve complete coverage of the forming area (the second area 162) in some cases, or in order to achieve complete coverage of the forming area, a wider scraper length and a larger powder spreading space are required, which increases the space of the forming bin and increases the cost of the equipment.

To this end, the present application proposes an optimized scraper structure, which can avoid the occurrence of the above-mentioned powder spreading situation and achieve a more precise powder spreading morphology.

As shown in reference to FIG7 , in some embodiments, the scraper is composed of a main scraper 121 and auxiliary scrapers 122 and 123 respectively arranged on both sides of the main scraper 121. When the scraper spreads powder on the forming platform 15, the main scraper 121 is only used for spreading powder in the second area 162; the auxiliary scrapers 122 and 123 are used for spreading powder in the first area 161, specifically for spreading powder on the upper side 161c of the first area and the lower side 161d of the first area. The auxiliary scrapers 122 and 123 are spaced apart from the main scraper 121 to form powder blocking dams 124 and 125 between the main scraper 121 and the auxiliary scrapers 122 and 123 to prevent the powder in the second area 162 from deviating outward. The powder blocking dams 124 and 125 can realize that the powder is mainly concentrated in the second area 162, avoid the trapezoidal structure in the second area 162, make more full use of the powder, and improve the utilization rate of the powder.

FIG7 shows that after the scraper of the present application lays the powder, a trapezoidal powder-blocking dam 124, 125 is formed between the main scraper 121 and the auxiliary scrapers 122, 123. The powder-blocking dam 124, 125 can make the powder move more along the area between the powder-blocking dam 124, 125, so that a more uniform powder laying is achieved in the second area 162 with the same amount of powder. As shown in FIG8, the scraper of the present application forms powder-blocking dams 124, 125 on the powder bed 16 along the movement trajectory during the powder laying process. The powder-blocking dams 124, 125 can avoid the appearance of a trapezoidal powder laying structure during the powder laying process.

In some embodiments, as shown in FIG. 7 , the height of the auxiliary scrapers 122 and 123 is set to be greater than the height of the main scraper 121, and the height difference between the two is the height difference between the second area 162 and the first area 161 (usually, after the powder is spread on the forming platform 15, there will be a small drop between the first powder bed 161 and the second powder bed 162). In this configuration, when the scraper acts on the powder bed 16, the main scraper 121 can be attached to the second area 162 for spreading powder, and the auxiliary scrapers 122 and 123 can be attached to the first area 161 for spreading powder, so as to avoid the scraper being suspended in the air.

In some embodiments, as shown in reference to Figures 11-12, in order to meet the scraper and powder lamination requirements of the forming platform 15 relative to the powder storage part 14 under height adjustment, the height of the main scraper 121 relative to the auxiliary scrapers 122, 123 in the present application is also set to be adjustable. Specifically, the scraper has a main body 21, and the auxiliary scrapers 122, 123 are fixed below the main body 21; a cavity 22 is provided in the main body 21, and electric telescopic rods 23, 24 are respectively provided at both ends of the top wall of the cavity 22, and one end of the electric telescopic rod 23, 24 is connected to the main scraper 121, and is used to drive the main scraper 121 to move in the Z-axis direction to adjust the height of the main scraper 121 relative to the auxiliary scrapers 122, 123. Among them, the other end of the electric telescopic rod 23, 24 is connected to the top wall of the cavity 22 (for example, fixed by bolts), that is, connected to the main body 21.

Among them, the electric telescopic rods 23, 24 are specifically a linear drive, which is mainly a new type of linear actuator composed of a drive motor, a gear reducer, and a telescopic rod body, etc., and can be considered as an extension of the drive motor in terms of structure. The electric telescopic rods 23, 24 are an electric drive device that converts the rotational motion of the motor into the linear reciprocating motion of the rod body, that is, it can perform linear reciprocating motion under the action of the motor. In one embodiment, the working parameters of the electric telescopic rods 23, 24 are: stroke 200mm, driving force ≤200/1600N, movement speed 7~180mm/s, input voltage DC12/24/36/~48V, and rated power 20W~30W.

According to one aspect of the present invention, a 3D printing device is provided, wherein the 3D printing device includes a structure in which the aforementioned powder spreading device is installed on the 3D printing device. In addition, a part of the structure of the 3D printing device itself has been described above.

Referring to FIG. 9 , a powder spreading method is provided according to one aspect of the present invention. The method is applied to the aforementioned powder spreading device and can also be applied to the aforementioned 3D printing equipment. The method is composed of at least steps S101-S103.

S101, driving the powder spreading part in the powder spreading direction to convey the powder overflowing from the powder bin through the powder storage part on the side close to the powder bin to the top of the forming platform for powder laying of the formed parts; S102, continuously driving the powder spreading part in the powder spreading direction to convey a part of the powder to the powder storage part on the side away from the powder bin;

S103, conveying the powder formed on the powder storage portion away from the powder bin in the opposite direction to the powder spreading direction to the forming platform for spreading.

Referring to FIG. 9 , a powder spreading method is provided according to one aspect of the present invention. The method is applied to the aforementioned powder spreading device and can also be applied to the aforementioned 3D printing device. The method is composed of at least steps S201-S204.

S201, continuously driving the powder spreading part in the powder spreading direction to convey the powder to the accumulation area on one side of the inclined platform away from one side of the powder bin; S202, controlling the vibration device to start to drive the inclined platform to vibrate;

S203, driving the powder spreading part to rise to a height at least greater than the highest point of the stacking area, and continuously driving the powder spreading part to move at the current height to a side of the stacking area away from the powder bin, and continuously driving the powder spreading part to descend to the original height; and

S204, conveying the powder formed on the side of the inclined platform away from the powder bin to the forming platform in the opposite direction of the powder spreading direction.

Since the technical implementation process of the steps corresponding to the method has been described in detail in the previous text, the method will not be described in detail here.

Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Reference numerals list

10…powder spreading device; 11…powder bin; 111…powder supply lifting device; 12…powder spreading part; 121…main scraper; 122, 123…auxiliary scrapers; 124, 125…powder intercepting and lifting device; 13…forming bin; 131…forming lifting device; 14…powder storage part; 15…forming platform; 16…powder bed; 161…first zone/first powder bed; 161a, 161b, 161c, 161d…left side, right side and lower side of the first zone; 162…second zone/second powder bed; 17…accumulating zone; 18…inclined platform; 19…vibrating device; 21…main body; 22…cavity; 23, 24…electric telescopic rod.

Claims

A powder spreading device, characterized by comprising:

A powder bin for storing powder for 3D printing; wherein the powder bin is capable of causing a portion of the powder to overflow from the powder bin under the action of a powder supply lifting device;

a powder spreading portion, used for conveying the powder overflowing from the powder bin in a direction away from the powder bin;

A forming bin, the forming bin comprising a powder storage portion and a forming platform disposed in the middle of the powder storage portion; at least a portion of the powder is pre-stored in the powder storage portion to form a first powder bed tending to a fixed form, and at least a portion of the powder is transported layer by layer by the powder spreading portion to the top of the forming platform to form a second powder bed for forming parts;

In which, the powder spreading section is configured to be able to transport the powder to the forming platform through the powder storage section close to the powder bin in one powder spreading direction, and continuously transport a portion of the powder to the powder storage section away from the powder bin, and reversely transport the powder formed on the powder storage section away from the powder bin to the forming platform in the opposite direction of the powder spreading direction.
The powder spreading device according to claim 1 is characterized in that the forming platform is configured to be driven to descend along the middle of the powder storage section in response to the forming of any layer of parts in the second powder bed.
The powder spreading device according to claim 2 is characterized in that the forming platform can rise or fall along the middle of the powder storage part under the drive of a forming lifting device.
The powder spreading device according to claim 1 is characterized in that the powder spreading part transports the powder back and forth between the powder storage part and the forming platform in a cycle until the powder is completely consumed, and then re-transports the powder newly overflowed from the powder bin.
The powder spreading device according to claim 1 is characterized in that the powder spreading part can move parallel to the powder spreading direction and can be lifted and lowered perpendicular to the powder spreading direction under the drive of a translation and lifting device.
The powder spreading device according to claim 5 is characterized in that an inclined platform is provided on a side of the powder storage portion away from the powder bin so that the powder transported to the corresponding area on this side forms an accumulation area on one side of the inclined platform.
The powder spreading device according to claim 6 is characterized in that the translation and lifting device is configured to drive the powder spreading part to rise to a height at least greater than the highest point of the stacking area when the powder spreading part moves to the side of the stacking area close to the powder bin, and continuously drive the powder spreading part to move at the current height to the side of the stacking area away from the powder bin, and continuously drive the powder spreading part to descend to the original height.
The powder spreading device according to claim 6 is characterized in that it also includes a vibration device capable of driving the inclined platform to vibrate.
The powder spreading device according to claim 6 is characterized in that the vibration device is arranged on the other side of the inclined platform and/or is arranged inside the inclined platform.
The powder spreading device according to claim 6 is characterized in that a heating device is provided inside the inclined platform.
The powder spreading device according to claim 1 is characterized in that the powder spreading part is a scraper.
The powder spreading device according to claim 11 is characterized in that the scraper consists of a main scraper and auxiliary scrapers respectively arranged on both sides of the main scraper.
The powder spreading device according to claim 12 is characterized in that when the scraper acts above the forming platform, the main scraper is used to spread powder on the forming platform.
The powder spreading device according to claim 13 is characterized in that the auxiliary scraper and the main scraper are spaced apart to form a powder retaining dam between the main scraper and the auxiliary scraper to prevent the powder on the forming platform from deviating outward.
The powder spreading device according to claim 12 is characterized in that the height of the main scraper relative to the auxiliary scraper is adjustable.
The powder spreading device according to claim 15 is characterized in that the scraper tool has a main body, and the auxiliary scraper is fixed below the main body; a cavity is arranged in the main body, and electric telescopic rods are respectively arranged at both ends of the top wall of the cavity, and one end of the electric telescopic rod is connected to the main scraper, which is used to drive the main scraper to move in the Z-axis direction to adjust the height of the main scraper relative to the auxiliary scraper.
A 3D printing device, characterized in that the 3D printing device includes a structure in which the powder spreading device according to any one of claims 1 to 16 is installed on the 3D printing device.
A powder spreading method, the method is applied to a structure comprising at least the powder spreading device according to claim 1, characterized in that the method comprises: driving the powder spreading part in a powder spreading direction to convey the powder overflowing from the powder bin through the powder storage part close to one side of the powder bin to the top of the forming platform for powder spreading of the formed part;

The powder spreading part is continuously driven in the powder spreading direction to convey a part of the powder to the powder storage part away from the powder bin; and the powder formed on the powder storage part away from the powder bin is reversely conveyed to the forming platform in the opposite direction of the powder spreading direction for laying.
A powder spreading method, the method being applied to a structure comprising at least the powder spreading device according to claim 8, characterized in that the method comprises: continuously driving the powder spreading part in the powder spreading direction to convey the powder to a stacking area on one side of the inclined platform away from one side of the powder bin;

Controlling the vibration device to start so as to drive the inclined platform to vibrate;

Drive the powder spreading part to rise to a height at least greater than the highest point of the stacking area, and continuously drive the powder spreading part to move at the current height to the side of the stacking area away from the powder bin, and continuously drive the powder spreading part down to the original height; and reversely transport the powder formed on the side of the inclined platform away from the powder bin to the forming platform in the opposite direction of the powder spreading direction.