Air adjusting system and air adjusting method of efficient powder-saving powder spreading device

Abstract

The invention relates to the technical field of metal additive manufacturing, and provides an air adjusting system and method of an efficient powder-saving powder spreading device, the air adjusting system comprises an air blowing opening and an air suction opening which are formed in the two sides of a forming chamber respectively and cover a forming breadth area, the air adjusting system further comprises a fan, and the fan communicates with the air blowing opening through an air blowing pipe; the draught fan is communicated with the air suction opening through an air suction pipe, a bypass pipe is arranged between the air blowing pipe and the air suction pipe, the bypass pipe is connected with an adjusting valve, and the air blowing pipe is connected with a first anemograph used for measuring the air speed of a main path and a second anemograph used for measuring the air speed of a branch path. By introducing the bypass pipe and the regulating valve, when the air speed of the original forming chamber is increased, the regulating valve is opened, the opening degree of the regulating valve is gradually increased, and total air generated by the fan is subjected to air distribution treatment, so that disturbance to an air field in the forming chamber in the operation process of the scraper is counteracted, and the stability of the air field in the forming chamber is improved; and the uniformity of the powder layer and the subsequent laser melting forming quality are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of metal additive manufacturing, and more particularly, to an air conditioning system and an air conditioning method for an efficient powder-saving powder spreading device. Background Art

[0002] Selective Laser Melting (SLM), also known as powder bed fusion 3D printing technology, is an important manufacturing technology in the field of 3D printing. This technology uses a laser energy source to scan a layer of flat metal powder in accordance with the path planned by a three-dimensional model, melting and solidifying it to achieve metallurgical bonding, thereby quickly manufacturing a high-density and high-strength metal component corresponding to the three-dimensional model.

[0003] During the powder spreading process in the forming chamber, when the scraper and the scraper assembly (hereinafter referred to as the scraper) pass through the forming area, they will disturb the air field in the forming chamber, especially the upper surface of the forming area. Specifically, as the scraper approaches the air outlet, passes through the center position, and then moves away from the air outlet, the wind speed on the upper surface of the forming area first increases and then decreases, causing the powder to be scraped away, resulting in waste and affecting the forming quality of the part. In addition, too fast a movement speed of the scraper will further increase the wind speed on the forming area, exacerbating the powder blowing phenomenon and also having an adverse effect on the forming quality. Currently, in order to avoid these problems, the prior art usually sets the scraper speed relatively slow, but this leads to an extended powder spreading time and restricts the improvement of the powder spreading efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide an air conditioning system and an air conditioning method for an efficient powder-saving powder spreading device, which solves the problem of powder blowing caused by the scraper disturbing the air field in the forming chamber during the powder spreading process.

[0005] The present invention is achieved through the following technical solutions: An air conditioning system for an efficient powder-saving powder spreading device includes an air outlet and an air inlet respectively provided on both sides of the forming chamber. Both the air outlet and the air inlet cover the forming area. The system further includes a fan, the fan is connected to the air outlet through an air blowing pipe, the fan is connected to the air inlet through an air suction pipe, a bypass pipe is provided between the air blowing pipe and the air suction pipe, a regulating valve is connected to the bypass pipe, a first anemometer for measuring the total wind speed and a second anemometer for measuring the branch wind speed are connected to the air blowing pipe, a first pipe valve is provided on the branch of the air blowing pipe, and a first filter is provided on the air suction pipe in front of the fan.

[0006] Further, one end of the bypass pipe is connected to the air suction pipe through an inclined tee, and the middle pipe of the inclined tee is inclined towards the return direction of the air suction pipe.

[0007] Further, the diameter of the air blowing pipe is R, the distance between the first anemometer and the fan is 4R - 5R, and the distance between the first anemometer and the connection point of the bypass pipe and the air blowing pipe is 4R - 5R.

[0008] Further, the distance between the second anemometer and the air blowing pipe is 4R to 5R, and the distance between the second anemometer and the connection point of the bypass pipe and the air blowing pipe is 4R to 5R.

[0009] Further, a second filter is provided at one end of the bypass pipe close to the air suction pipe.

[0010] Further, a second pipe valve is provided on the main path of the air suction pipe, and a third pipe valve is provided on the branch path of the air suction pipe.

[0011] Further, both the air blowing port and the air suction port are arranged in an open shape along the sliding direction of the blade, and are flush with the upper surface of the forming web.

[0012] An air adjustment method includes the following steps:

[0013] Step S1, start the printing device and the fan, and keep the blade speed and the fan air speed unchanged;

[0014] Step S2, according to the relative position of the blade and the air blowing port or the air suction port, adjust the opening and closing and the opening degree of the regulating valve in real time.

[0015] Further, step S2 includes:

[0016] When the blade moves to the edge of the air blowing port or the air suction port, the regulating valve closes;

[0017] When the blade moves towards the midpoint position of the air blowing port or the air suction port, the regulating valve opens, and the opening degree gradually increases;

[0018] When the blade gradually moves away from the midpoint position of the air blowing port or the air suction port, the regulating valve opens, and the opening degree gradually decreases.

[0019] Further, the wind speeds detected by the first anemometer and the second anemometer are V 0 and V 1 , then the wind speed of the bypass pipe is V 3 =V 0 -V 1 , the opening degree adjustment speed of the regulating valve is positively correlated with the moving speed of the blade, the opening degree of the regulating valve is positively correlated with the wind speed V 3 of the bypass pipe, and the wind speed V 3 of the bypass pipe is negatively correlated with the distance between the blade and the midpoint position of the air blowing port or the air suction port.

[0020] The present invention has at least the following advantages and beneficial effects:

[0021] (1) By introducing the bypass pipe and the regulating valve, when the wind speed in the original forming chamber increases, the regulating valve is opened and the opening degree of the regulating valve is gradually increased to divide the total air generated by the fan, so as to offset the disturbance of the air field in the forming chamber during the operation of the scraper, improve the stability of the air field in the forming chamber, and ensure the uniformity of the powder layer and the quality of subsequent laser melting forming.

[0022] (2) Through the setting of the first anemometer and the second anemometer and the design of the installation position, the change of the wind speed can be monitored accurately in real time, providing reliable data support for the air volume regulation.

[0023] (3) Through the setting of the first filter and the second filter, the cleanliness of the air path in the forming chamber is ensured, the service life of the equipment is extended, and at the same time, the second filter has a self-cleaning function. Description of the Drawings

[0024] Figure 1 It is a schematic connection diagram of the air regulating system and the forming chamber of an efficient powder-saving powder spreading device provided by the present invention.

[0025] Figure 2 It is a sectional view of the forming chamber in the present invention.

[0026] Figure 3 It is a schematic structural diagram of the air regulating system of an efficient powder-saving powder spreading device provided by the present invention.

[0027] Figure 4 It is a flowchart of an air regulating method provided by the present invention.

[0028] Reference Numerals: 1 - forming chamber, 11 - forming width, 12 - powder receiving area, 13 - scraper, 14 - linear module, 15 - air blowing port, 16 - air suction port, 2 - fan, 3 - air blowing pipe, 31 - first anemometer, 32 - second anemometer, 33 - first pipe valve, 4 - air suction pipe, 41 - first filter, 42 - second pipe valve, 43 - third pipe valve, 5 - bypass pipe, 51 - regulating valve, 52 - inclined tee, 53 - second filter. Detailed Embodiments

[0029] The following are the detailed embodiments in conjunction with the drawings.

[0030] Embodiment

[0031] As Figures 1 to 3As shown, in this embodiment, a wind adjustment system for an efficient powder-saving powder spreading device is mainly disclosed, which includes a blowing port 15 and a suction port 16 respectively arranged on both sides of the forming chamber 1. Both the blowing port 15 and the suction port 16 cover the forming width area 11. It also includes a fan 2. The fan 2 is connected to the blowing port 15 through a blowing pipe 3, and the fan 2 is connected to the suction port 16 through a suction pipe 4. A bypass pipe 5 is arranged between the blowing pipe 3 and the suction pipe 4. A regulating valve 51 is connected to the bypass pipe 5. A first anemometer 31 for measuring the total path wind speed and a second anemometer 32 for measuring the branch path wind speed are connected to the blowing pipe 3. A first pipe valve 33 is arranged on the branch path of the blowing pipe 3. A first filter 41 is arranged in front of the fan 2 on the suction pipe 4. Specifically, the forming chamber 1 includes a forming width 11, a powder receiving area 12, a scraper 13, and a linear module 14 for driving the scraper 13 to reciprocate linearly. The linear modules 14 are respectively arranged on both sides of the forming width 11, and the scraper 13 spans above the forming width 11. During the forming and printing process of the equipment, the powder spreading action of the device is that the scraper 13 pushes the powder in the powder receiving area 12 onto the forming width 11, and the wind is drawn away from the suction port 16 after passing through the forming width 11 from the blowing port 15. Through the cooperation of the blowing port 15 and the suction port 16, the wind field distribution in the forming chamber can be effectively controlled, and the phenomenon of powder being scraped away can be reduced. By introducing the bypass pipe 5 and the regulating valve 51, the air volume flowing through the forming width 11 can be dynamically adjusted according to actual needs, improving the flexibility and adaptability of the system. The settings of the first anemometer 31 and the second anemometer 32 can monitor the wind speed changes in real time and provide data support for air volume adjustment. The first pipe valve 33 can be used as the main control valve of the entire wind adjustment system, and the opening and closing of the first pipe valve 33 directly control the on-off of the wind path in the forming chamber 1. The first filter 41 is arranged on the main return air path of the suction pipe 4 to filter the ash and slag inhaled during the overall working process, provide a clean argon atmosphere for the forming chamber, and at the same time, prevent the ash and slag from entering the fan 2 and extend the service life of the equipment.

[0032] Furthermore, during specific implementation, one end of the bypass pipe 5 provided in the embodiment of the present invention is connected to the suction pipe 4 through an inclined tee 52, and the middle pipe of the inclined tee 52 is inclined towards the return direction of the suction pipe 4. Specifically, the inclined middle pipe of the inclined tee 52 can adopt a straight pipe or a bent pipe for transition, which can reduce the resistance of the air flow and improve the efficiency of the fan 2. The middle pipe of the inclined tee 52 is inclined towards the return direction of the suction pipe 4, effectively avoiding the branch flow of the wind entering from the suction port 16 to the branch path of the bypass pipe 5, contributing to the smooth transition of the air flow and avoiding the generation of turbulent flow.

[0033] Further, in specific implementation, the diameter of the above-mentioned air blowing pipe 3 provided in the embodiment of the present invention is D. The distance between the first anemometer 31 and the blower 2 is 4D to 5D, and the distance between the first anemometer 31 and the connection point of the bypass pipe 5 and the air blowing pipe 3 is 4D to 5D. Preferably, the distance between the second anemometer 32 and the air blowing pipe 3 is 4D to 5D, and the distance between the second anemometer 32 and the connection point of the bypass pipe 5 and the air blowing pipe 3 is 4D to 5D. This can avoid the turbulence interference at the outlet of the blower 2, the connection of the bypass pipe 5, and the inlet of the air blowing port 15, ensuring the accuracy of the wind speed measurement of the first anemometer 31 and the second anemometer 32. At the same time, it provides reliable data for the calculation of the bypass wind speed of the bypass pipe 5. In addition, the installation positions of the first anemometer 31 and the second anemometer 32 are designed based on the ratio of the diameter D of the air blowing pipe 3, facilitating the standardization and modularization of the system.

[0034] Further, in specific implementation, a second filter 53 is provided at one end of the above-mentioned bypass pipe 5 close to the air suction pipe 4. Specifically, the second filter 53 is arranged on the bypass pipe 5. When the regulating valve 51 is closed, it can prevent ash and slag from entering the regulating valve 51, extending the service life of the equipment. When the regulating valve 51 is opened, on the one hand, it can prevent ash and slag and the black smoke generated during the laser sintering process of the equipment from entering the forming chamber 1 through the bypass pipe 5 and the air suction pipe 4, ensuring the cleanliness of the air path in the forming chamber 1; on the other hand, the air diverted from the blower 2 to the bypass pipe 5 can clean the second filter 53 to a certain extent, taking away the ash and slag attached to the second filter 53 and going to the first filter 41 for filtration.

[0035] Further, in specific implementation, a second pipe valve 42 is provided on the main path of the above-mentioned air suction pipe 4, and a third pipe valve 43 is provided on the branch path of the air suction pipe 4. Through the cooperation of the first pipe valve 33, the second pipe valve 42, the third pipe valve 43, and the regulating valve 51, the safe replacement of the first filter 41 and the second filter 53 can be realized.

[0036] Further, in specific implementation, both the above-mentioned air blowing port 15 and the air suction port 16 are arranged in an open shape along the sliding direction of the scraper 13 and are flush with the upper surface of the forming width 11. Specifically, the open length of the air blowing port 15 and the air suction port 16 is greater than the length of the forming width 11, ensuring that the wind field formed by the air blowing port 15 and the air suction port 16 can evenly cover the forming width 11, reducing the phenomenon of too high or too low local wind speed and effectively reducing the situation where the powder is scraped away.

[0037] As Figure 4 shown, in this embodiment, a method for adjusting the air volume of an air volume adjustment system based on the above-mentioned high-efficiency powder-saving powder spreading device is also disclosed, including the following steps:

[0038] Step S1: Start the printing device and the blower 2, and keep the speed of the doctor blade 13 and the wind speed of the blower 2 unchanged; during the powder spreading process of the doctor blade 13, the speed of the doctor blade 13 and the wind speed of the blower 2 do not need to be adjusted or changed, which can shorten the powder spreading time and improve the powder spreading efficiency.

[0039] Step S2: Adjust the opening and closing and the opening degree of the regulating valve 51 in real time according to the relative position of the doctor blade 13 and the air blowing port 15 or the air suction port 16.

[0040] It should be noted that when the doctor blade 13 approaches the air blowing port 15, the movement of the doctor blade 13 will form a local high-pressure area in front of it, resulting in an acceleration of the air flow. At this time, the air flow at the air blowing port 15 is superimposed on the air flow generated by the movement of the doctor blade 13, increasing the wind speed on the upper surface of the forming width 11. When the doctor blade 13 moves away from the air blowing port 15, the doctor blade 13 continues to move and gradually moves away from the air blowing port 15, and the high-pressure area in front of it weakens, and the wind speed decreases accordingly. The change in wind speed will directly affect the stability of the powder layer. When the wind speed increases, the scouring effect of the air flow on the powder increases. If the wind speed is too high, some powder will be blown away from the forming width 11, resulting in powder waste; when the wind speed decreases, the scouring effect of the air flow on the powder weakens, but due to the sudden change in wind speed, the powder layer may be uneven, affecting the subsequent laser melting and forming quality.

[0041] The principle of the air flow regulation method provided by the present invention is that based on the influence of the movement of the doctor blade 13 on the change of the air speed in the forming chamber 1, a bypass pipe 5 is introduced. When the air speed in the original forming chamber 1 increases, the regulating valve 51 is opened, and the opening degree of the regulating valve 51 is gradually increased to perform air distribution on the total air generated by the blower 2, so as to offset the disturbance of the air field in the forming chamber 1 during the operation of the doctor blade 13.

[0042] Further, in specific implementation, step S2 provided in the embodiment of the present invention includes:

[0043] When the doctor blade 13 moves to the edge of the air blowing port 15 or the air suction port 16, the regulating valve 51 is closed;

[0044] When the doctor blade 13 moves towards the midpoint position of the air blowing port 15 or the air suction port 16, the regulating valve 51 is opened, and the opening degree gradually increases;

[0045] When the doctor blade 13 gradually moves away from the midpoint position of the air blowing port 15 or the air suction port 16, the regulating valve 51 is opened, and the opening degree gradually decreases.

[0046] Further, in specific implementation, the wind speeds detected by the first anemometer 31 and the second anemometer 32 are respectively V 0 and V 1 , then the wind speed of the bypass pipe 5 is V 3 =V 0 -V 1 ;

[0047] The opening adjustment speed of the regulating valve 51 is positively correlated with the moving speed of the blade 13. The opening of the regulating valve 51 is positively correlated with the wind speed V of the bypass pipe 5 3 and the wind speed V of the bypass pipe 5 3 is negatively correlated with the distance of the blade 13 from the midpoint position of the air outlet 15 or the air inlet 16.

Claims

1. An air conditioning system for a high-efficiency powder-saving powder spreading device, comprising a blowing port (15) and an air suction port (16) respectively arranged on both sides of a forming chamber (1), wherein the blowing port (15) and the air suction port (16) both cover the forming surface (11) area, and characterized in that: The invention also comprises a fan (2), wherein the fan (2) is connected to the blowing port (15) via a blowing pipe (3), and the fan (2) is connected to the suction port (16) via a suction pipe (4). A bypass pipe (5) is provided between the blowing pipe (3) and the suction pipe (4), and a regulating valve (51) is connected to the bypass pipe (5). The blowing pipe (3) is connected to a first anemometer (31) for measuring the wind speed of the total line and a second anemometer (32) for measuring the wind speed of the branch line. A first pipe valve (33) is provided on the branch line of the blowing pipe (3), and a first filter (41) is provided on the suction pipe (4) in front of the fan (2).

2. The air conditioning system of the high-efficiency powder-saving powder spreading device according to claim 1 is characterized in that: One end of the bypass pipe (5) is connected to the air suction pipe (4) via an oblique tee (52), and the middle pipe of the oblique tee (52) is inclined toward the return direction of the air suction pipe (4).

3. The air conditioning system of the high-efficiency powder-saving powder spreading device according to claim 1 is characterized in that: The diameter of the blowing pipe (3) is D, the distance between the first anemometer (31) and the fan (2) is 4D to 5D, and the distance between the first anemometer (31) and the connection point between the bypass pipe (5) and the blowing pipe (3) is 4D to 5D.

4. The air conditioning system of the high-efficiency powder-saving powder spreading device according to claim 3 is characterized in that: The distance between the second anemometer (32) and the blowing pipe (3) is 4D to 5D, and the distance between the second anemometer (32) and the connection point between the bypass pipe (5) and the blowing pipe (3) is 4D to 5D.

5. The air conditioning system of the high-efficiency powder-saving powder spreading device according to claim 1 is characterized in that: A second filter (53) is provided at one end of the bypass pipe (5) close to the air suction pipe (4).

6. The air conditioning system of the high-efficiency powder-saving powder spreading device according to claim 1 is characterized in that: The main line of the air suction pipe (4) is provided with a second pipe valve (42), and the branch line of the air suction pipe (4) is provided with a third pipe valve (43).

7. The air conditioning system of the high-efficiency powder-saving powder spreading device according to claim 1 is characterized in that: The blowing port (15) and the suction port (16) are both arranged in an open manner along the sliding direction of the scraper (13) and are flush with the upper surface of the forming web (11).

8. An air regulating method for an air regulating system of an efficient powder-saving powder spreading device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1, starting the printing device and the fan (2), keeping the speed of the scraper (13) and the wind speed of the fan (2) unchanged; Step S2: adjusting the opening and closing and the opening degree of the regulating valve (51) in real time according to the relative position of the scraper (13) and the blowing port (15) or the suction port (16).

9. The air conditioning method according to claim 8, characterized in that: The step S2 comprises: When the scraper (13) moves to the edge of the air blowing port (15) or the air suction port (16), the regulating valve (51) is closed; When the scraper (13) moves toward the midpoint of the air blowing port (15) or the air suction port (16), the regulating valve (51) opens, and the opening degree gradually increases; When the scraper (13) gradually moves away from the midpoint of the air blowing port (15) or the air suction port (16), the regulating valve (51) opens, and the opening degree gradually decreases.

10. The air conditioning method according to claim 8, characterized in that: The wind speeds detected by the first anemometer (31) and the second anemometer (32) are obtained as V0 and V1 respectively, and the wind speed of the bypass pipe (5) is V3 = V0-V1; The opening adjustment speed of the regulating valve (51) is positively correlated with the moving speed of the scraper (13), the opening of the regulating valve (51) is positively correlated with the wind speed V3 of the bypass pipe (5), and the wind speed V3 of the bypass pipe (5) is negatively correlated with the distance between the scraper (13) and the midpoint of the blowing port (15) or the suction port (16).

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