A laser-based self-feedback additive control robot

Abstract

This invention provides a laser-based self-feedback additive manufacturing control robot. A scraper powder-spreading mechanism is located on the top of a base. A reciprocating drive mechanism for driving the scraper powder-spreading mechanism is located between the base and the scraper powder-spreading mechanism. The scraper powder-spreading mechanism includes a powder storage container with a top opening, a powder discharging gate assembly on the container, and a lifting scraper assembly and a lifting pressure roller assembly at the bottom of the container. A first laser rangefinder is located on one side of the container along the movement direction of the scraper powder-spreading mechanism. A baffle is located on one side of the top of the base. The invention also includes a controller that controls the reciprocating drive mechanism and the alternating lifting and lowering of the lifting scraper assembly and the lifting pressure roller assembly based on the signal from the first laser rangefinder. This invention achieves simple and rapid switching of additive manufacturing control states by using the first laser rangefinder to detect the distance between the robot and the baffle in real time, and the controller controls the reciprocating drive mechanism, the lifting scraper assembly, and the lifting pressure roller assembly based on the distance signal. This results in good stability and small cumulative motion error.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically a laser-based self-feedback additive control robot. Background Technology

[0002] Selective Laser Melting (SLM) is a novel manufacturing method that uses a high-energy laser beam to selectively melt flattened powder based on the principle of layer cutting and stacking. This allows the powder metal to be deposited layer by layer to form a part with low porosity and good mechanical properties.

[0003] Powder spreading is a key process in selective laser melting (SLM). Existing SLM forming equipment mostly uses single-pass, single-scraper powder spreading, resulting in long powder spreading idle times and poor powder spreading quality. A few devices use bidirectional powder spreading mechanisms, but these suffer from complex structures and poor stability. Furthermore, these devices use fixed motion ranges or fixed-point collision triggering to control motion state switching and movement, leading to slow state switching, large cumulative motion errors, and a lack of self-correction capabilities. To address these problems, this invention provides a simple dual-blade, bidirectional laser-based self-feedback additive manufacturing control robot. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art and to provide a laser-based self-feedback additive control robot.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A laser-based self-feedback additive manufacturing control robot includes a base with a forming cavity. A scraper powder spreading mechanism is located on the top of the base, and a powder storage and discharging mechanism is located above the scraper powder spreading mechanism. A reciprocating drive mechanism for driving the scraper powder spreading mechanism is provided between the base and the scraper powder spreading mechanism. The scraper powder spreading mechanism includes a powder storage container with a top opening and a powder discharging port at the bottom. A powder discharging gate assembly that cooperates with the powder discharging port is provided on the powder storage container. A lifting scraper assembly and a lifting pressure roller assembly are located at the bottom of the powder storage container. The powder storage container moves along the scraper powder spreading mechanism... A first laser rangefinder is provided on one side of the direction of movement. The first laser rangefinder is arranged along the direction of movement of the scraper powder spreading mechanism. A baffle is provided on one side of the top of the base opposite to the first laser rangefinder. The laser-type self-feedback additive manufacturing control robot also includes a controller. The first laser rangefinder, the powder storage and feeding mechanism, the reciprocating drive mechanism, the powder feeding gate assembly, the lifting scraper assembly, and the lifting pressure roller assembly are respectively connected to the controller. The controller can control the reciprocating drive mechanism and the lifting scraper assembly and the lifting pressure roller assembly to rise and fall alternately according to the signal of the first laser rangefinder.

[0007] Preferably, the reciprocating drive mechanism is an electric linear guide mechanism.

[0008] Preferably, the powder discharge door assembly includes a powder discharge door, the powder storage container is provided with a slide groove that is slidably connected to the powder discharge door, the slide groove is provided with a first spring and a first cam, the two ends of the first spring are respectively connected to the powder discharge door and the inner wall of the slide groove, the first cam abuts against the powder discharge door, and the first cam is connected to a first motor for driving the first cam.

[0009] Preferably, the lifting scraper assembly includes a scraper and a first connecting rod. The bottom of the powder storage container is provided with a first receiving cavity. A first guide plate that slides and cooperates with the first connecting rod is fixed in the first receiving cavity. The scraper is fixed at the bottom end of the first connecting rod. A first roller is provided at the top end of the first connecting rod. A second cam is provided in the first receiving cavity. The second cam abuts against the first roller and is connected to a second motor for driving the second cam.

[0010] Preferably, the lifting roller assembly includes a pressure roller and a second connecting rod. The bottom of the powder storage container is provided with a second receiving cavity. A second guide plate that slides and cooperates with the second connecting rod is fixed in the second receiving cavity. The roller shaft is provided at the bottom end of the second connecting rod. A second roller is provided at the top end of the second connecting rod. A third cam is provided in the second receiving cavity. The third cam abuts against the second roller and is connected to a third motor for driving the third cam.

[0011] Preferably, the powder storage and feeding mechanism includes a storage hopper, and an electric valve is provided at the bottom of the storage hopper.

[0012] Preferably, the powder storage container is further provided with a second laser rangefinder and a third laser rangefinder. The second laser rangefinder and the third laser rangefinder are located at the same height and are both vertically downward. The second laser rangefinder and the third laser rangefinder are spaced apart in a horizontal direction perpendicular to the movement direction of the scraper powder spreading mechanism. The second laser rangefinder and the third laser rangefinder are respectively connected to the controller signal.

[0013] Preferably, the molding cavity is provided with a lifting base plate, and the bottom of the lifting base plate is connected to a telescopic element, the bottom end of which is fixedly connected to the base.

[0014] Preferably, the base is further provided with a recycling chamber, the bottom end of which extends to one side of the base, and a recycling chamber door is hinged to one side of the base.

[0015] Preferably, the laser-based self-feedback additive control robot further includes a cover disposed on the top of the base, and the baffle is part of the cover.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] The laser-based self-feedback additive manufacturing control robot of this invention uses a first laser rangefinder to detect the distance between itself and the baffle in real time. The controller then controls the reciprocating drive mechanism and the alternating lifting of the lifting scraper assembly and lifting pressure roller group based on the distance signal, achieving simple and rapid switching of the additive manufacturing control state. This results in good stability and low cumulative motion error. Furthermore, the real-time detection by a second and third laser rangefinder can reflect the flatness of the powder layer, improving the quality of the printed parts. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of the laser-type self-feedback additive control robot of the present invention;

[0019] Figure 2 This is a top view of the laser-based self-feedback additive control robot of the present invention;

[0020] Figure 3 This is a schematic diagram of the scraper powder spreading mechanism in this invention;

[0021] Figure 4 for Figure 3 Enlarged view of the structure of section A;

[0022] Figure 5 for Figure 3 Enlarged view of the structure of part B.

[0023] Explanation of reference numerals in the attached figures

[0024] 1-Base, 2-Forming cavity, 3-Scraper powder spreading mechanism, 4-Powder storage and discharge mechanism, 5-Reciprocating drive mechanism, 6-Powder storage container, 7-Powder discharge port, 8-First laser rangefinder, 9-Baffle, 10-Powder discharge door, 11-Groove, 12-First spring, 13-First cam, 14-Scraper, 15-First connecting rod, 16-First receiving cavity, 17-First guide plate, 18-First roller, 19-Second cam, 20-Pressure roller, 21-Second connecting rod, 22-Second receiving cavity, 23-Second guide plate, 24-Second roller, 25-Third cam, 26-Storage hopper, 27-Electric valve, 28-Second laser rangefinder, 29-Third laser rangefinder, 30-Lifting base plate, 31-Telescopic element, 32-Recovery cavity, 33-Recovery cavity door. Detailed Implementation

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0026] like Figures 1 to 5 As shown, a laser-based self-feedback additive manufacturing control robot includes a base 1 with a forming cavity 2. A scraper powder spreading mechanism 3 is located on the top of the base 1, and a powder storage and discharging mechanism 4 is located above the scraper powder spreading mechanism 3. A reciprocating drive mechanism 5 for driving the scraper powder spreading mechanism 3 is located between the base 1 and the scraper powder spreading mechanism 3. The scraper powder spreading mechanism 3 includes a powder storage container 6 with an opening at the top, a powder discharging port 7 at the bottom of the powder storage container 6, a powder discharging gate assembly that cooperates with the powder discharging port 7, and a lifting scraper assembly and a lifting pressure roller assembly at the bottom of the powder storage container 6. The powder storage container 6 moves along the scraper... A first laser rangefinder 8 is provided on one side of the movement direction of the blade powder spreading mechanism 3. The first laser rangefinder 8 is arranged along the movement direction of the blade powder spreading mechanism 3. A baffle 9 is provided on one side of the top of the base 1, which is opposite to the first laser rangefinder 8. The laser-type self-feedback additive manufacturing control robot also includes a controller. The first laser rangefinder 8, the powder storage and feeding mechanism 4, the reciprocating drive mechanism 5, the powder feeding gate assembly, the lifting scraper assembly, and the lifting pressure roller assembly are respectively connected to the controller. The controller can control the reciprocating drive mechanism 5, as well as the lifting scraper assembly and the lifting pressure roller assembly, to rise and fall alternately according to the signal of the first laser rangefinder 8.

[0027] Specifically, in this embodiment, when the laser-type self-feedback additive manufacturing control robot is not working, the scraper powder spreading mechanism 3 is located directly below the powder storage and discharging mechanism 4, and the baffle 9 and the scraper powder spreading mechanism 3 are located on both sides above the forming cavity 2, respectively. When starting work, the controller controls the powder storage and discharging mechanism 4 to discharge powder, and the powder falls into the powder storage container 6 of the scraper powder spreading mechanism 3. After the powder storage and discharging mechanism 4 discharges powder for a set time, the controller controls the reciprocating drive mechanism 5 to drive the scraper powder spreading mechanism 3 to start moving forward toward the baffle 9. At the same time, the controller controls the powder discharging gate assembly to open, the lifting scraper assembly to descend, and the lifting pressure roller assembly to rise. The lifting scraper assembly scrapes the powder falling from the powder discharging port 7. During the forward movement of the scraper powder spreading mechanism 3, the first laser rangefinder 8 continuously monitors the distance to the baffle 9 and sends the distance signal to the controller. When the distance between the first laser rangefinder 8 and the baffle 9 reaches a first set value, the controller controls the reciprocating drive mechanism 5 to drive the scraper powder spreading mechanism 3 back, simultaneously controlling the powder falling door assembly to close, the lifting scraper assembly to rise, and the lifting pressure roller assembly to fall, compacting the powder through the lifting pressure roller assembly. Similarly, during the return movement of the scraper powder spreading mechanism 3, the first laser rangefinder 8 continuously monitors the distance to the baffle 9 and sends the distance signal to the controller. When the distance between the first laser rangefinder 8 and the baffle 9 reaches a second set value, the controller controls the reciprocating drive mechanism 5 to drive the scraper powder spreading mechanism 3 forward again, repeating the above process.

[0028] In this embodiment, the laser-type self-feedback additive control robot uses the first laser rangefinder 8 to detect the distance between itself and the baffle 9 in real time. The controller controls the reciprocating drive mechanism to move back and forth according to the distance signal, as well as the lifting scraper assembly and the 20 sets of lifting pressure rollers to alternately lift and lower, so as to realize the simple and quick switching of the additive control working state, with good stability and small cumulative motion error.

[0029] In some embodiments, the reciprocating drive mechanism 5 is an electric linear guide mechanism, and the powder storage container 6 is connected to the slider of the electric linear guide mechanism via a bracket. The electric linear guide mechanism is prior art, and its structure and principle will not be described in detail in this embodiment.

[0030] In some embodiments, the powder discharge door assembly includes a powder discharge door 10. The powder storage container 6 is provided with a slide groove 11 that is slidably connected to the powder discharge door 10. A first spring 12 and a first cam 13 are provided in the slide groove 11. The two ends of the first spring 12 are respectively connected to the powder discharge door 10 and the inner wall of the slide groove 11. The first cam 13 abuts against the powder discharge door 10. The first cam 13 is connected to a first motor for driving the first cam 13. The first motor is signal-connected to a controller. The first spring 12 is a tension spring. The rotation of the first cam 13, through its outer contour and under the action of the first spring 12, enables the opening and closing of the powder discharge door 10. It should be noted that the powder discharge door assembly is not limited to the above form and can also be in other forms.

[0031] In some embodiments, the lifting scraper assembly includes a scraper 14 and a first connecting rod 15. The powder storage container 6 has a first receiving cavity 16 at its bottom. A first guide plate 17, which slides and engages with the first connecting rod 15, is fixed inside the first receiving cavity 16. The scraper 14 is fixed to the bottom end of the first connecting rod 15. A first roller 18 is provided at the top end of the first connecting rod 15. A second cam 19 is provided inside the first receiving cavity 16. The second cam 19 abuts against the first roller 18 and is connected to a second motor for driving the second cam 19. The second motor is signal-connected to a controller. The first connecting rod 15 is vertically arranged, and the first roller 18 is positioned above the second cam 19. When the second cam 19 rotates, it can drive the first roller 18 to rise and fall, thereby driving the first connecting rod 15 and the scraper 14 to rise and fall.

[0032] In some embodiments, the lifting roller assembly includes a pressure roller 20 and a second connecting rod 21. The powder storage container 6 has a second receiving cavity 22 at its bottom. A second guide plate 23, which slides within the second receiving cavity 22, is fixed therein and is slidably engaged with the second connecting rod 21. The roller shaft is located at the bottom end of the second connecting rod 21. A second roller 24 is located at the top end of the second connecting rod 21. A third cam 25 is located within the second receiving cavity 22. The third cam 25 abuts against the second roller 24 and is connected to a third motor for driving the third cam 25. The lifting principle of the lifting roller assembly in this embodiment is the same as that of the lifting scraper assembly, and will not be described again in this embodiment. It should be noted that the lifting scraper assembly and the lifting roller assembly in this embodiment can achieve the effect of leveling and compacting the powder entirely by relying on the gravity of the scraper 14 and the pressure roller 20.

[0033] In some embodiments, the powder storage and feeding mechanism 4 includes a storage hopper 26, and the bottom end of the storage hopper 26 is provided with an electric valve 27, which is connected to the controller signal.

[0034] In some embodiments, the powder storage container 6 is further provided with a second laser rangefinder 28 and a third laser rangefinder 29. The second laser rangefinder 28 and the third laser rangefinder 29 are located at the same height and are both vertically downward. The second laser rangefinder 28 and the third laser rangefinder 29 are spaced apart along a horizontal direction perpendicular to the movement direction of the scraper powder spreading mechanism 3. The second laser rangefinder 28 and the third laser rangefinder 29 are respectively connected to the controller signal. Specifically, the second laser rangefinder 28 and the third laser rangefinder 29 can be located on the same side of the powder storage container 6 as the first laser rangefinder 8. In this embodiment, an L-shaped plate is provided on one side of the powder storage container 6, and the first, second, and third laser rangefinders are all located on the L-shaped plate. During the operation of the laser-based self-feedback additive manufacturing control robot, the second laser rangefinder 28 and the third laser rangefinder 29 measure the distance between the two points of the doctor blade powder spreading mechanism 3 and the horizontal plane of the base 1 in real time. The difference in distance signals is used to determine the levelness of the doctor blade powder spreading mechanism 3, which in turn reflects the flatness of the powder layer in the forming cavity 2. When the difference in distance signals is large, an alarm can be set and connected to the controller. If the tilt angle is too large, it will remind the operator to correct the levelness of the doctor blade powder spreading mechanism 3 if necessary, thereby improving the quality of the printed parts.

[0035] In some embodiments, the forming cavity 2 is provided with a lifting base plate 30, and the bottom of the lifting base plate 30 is connected to a telescopic element 31, the bottom end of which is fixedly connected to the base 1. When the forming cavity 2 is in working condition, the telescopic element 31 drives the lifting base plate 30 to descend a predetermined height, and then waits for the doctor blade powder spreading mechanism 3 to spread powder and for laser printing to begin.

[0036] In some embodiments, the base 1 is further provided with a recycling chamber 32, the bottom end of which extends to one side of the base 1. A recycling chamber door 33 is hinged to one side of the base 1. The recycling chamber 32 is used to recycle excess powder. However, when the powder in the recycling chamber 32 accumulates to a certain amount, the recycling chamber door 33 can be opened to take out the powder in the recycling chamber 32 for use.

[0037] In some embodiments, the laser-based self-feedback additive control robot further includes a cover disposed on top of the base 1, and the baffle 9 is part of the cover.

Claims

1. A laser-based self-feedback additive manufacturing control robot, characterized in that, The system includes a base with a forming cavity. A scraper powder-spreading mechanism is located on the top of the base, and a powder storage and discharging mechanism is located above the scraper powder-spreading mechanism. A reciprocating drive mechanism for driving the scraper powder-spreading mechanism is located between the base and the scraper powder-spreading mechanism. The scraper powder-spreading mechanism includes a powder storage container with a top opening, a powder discharging port at the bottom of the powder storage container, a powder discharging gate assembly that cooperates with the powder discharging port, a lifting scraper assembly and a lifting pressure roller assembly at the bottom of the powder storage container, and a side of the powder storage container along the movement direction of the scraper powder-spreading mechanism. The system includes a first laser rangefinder, which is positioned along the movement direction of the scraper powder spreading mechanism. A baffle is provided on one side of the top of the base, opposite to the first laser rangefinder. The laser-type self-feedback additive manufacturing control robot also includes a controller. The first laser rangefinder, powder storage and feeding mechanism, reciprocating drive mechanism, powder feeding gate assembly, lifting scraper assembly, and lifting pressure roller assembly are respectively connected to the controller via signals. The controller can control the reciprocating drive mechanism and the lifting scraper assembly and lifting pressure roller assembly to alternately lift and lower according to the signal from the first laser rangefinder. The lifting scraper assembly includes a scraper and a first connecting rod. The bottom of the powder storage container is provided with a first receiving cavity. A first guide plate that slides and cooperates with the first connecting rod is fixed in the first receiving cavity. The scraper is fixed at the bottom end of the first connecting rod. A first roller is provided at the top end of the first connecting rod. A second cam is provided in the first receiving cavity. The second cam abuts against the first roller and is connected to a second motor for driving the second cam. The lifting roller assembly includes a pressure roller and a second connecting rod. The bottom of the powder storage container is provided with a second receiving cavity. A second guide plate that slides with the second connecting rod is fixed in the second receiving cavity. The roller shaft is provided at the bottom end of the second connecting rod. A second roller is provided at the top end of the second connecting rod. A third cam is provided in the second receiving cavity. The third cam abuts against the second roller and is connected to a third motor for driving the third cam.

2. The laser-based self-feedback additive control robot according to claim 1, characterized in that: The reciprocating drive mechanism is an electric linear guide mechanism.

3. The laser-based self-feedback additive control robot according to claim 1, characterized in that: The powder discharge door assembly includes a powder discharge door, and the powder storage container is provided with a slide groove that is slidably connected to the powder discharge door. A first spring and a first cam are provided in the slide groove. The two ends of the first spring are respectively connected to the powder discharge door and the inner wall of the slide groove. The first cam abuts against the powder discharge door, and the first cam is connected to a first motor for driving the first cam.

4. The laser-based self-feedback additive control robot according to claim 1, characterized in that: The powder storage and feeding mechanism includes a storage hopper, and an electric valve is provided at the bottom of the storage hopper.

5. A laser-based self-feedback additive control robot according to claim 1, characterized in that: The powder storage container is also equipped with a second laser rangefinder and a third laser rangefinder. The second laser rangefinder and the third laser rangefinder are located at the same height and are both vertically downward. The second laser rangefinder and the third laser rangefinder are spaced apart in a horizontal direction perpendicular to the movement direction of the scraper powder spreading mechanism. The second laser rangefinder and the third laser rangefinder are respectively connected to the controller signal.

6. A laser-based self-feedback additive control robot according to claim 1, characterized in that: The molding cavity is provided with a lifting base plate, and the bottom of the lifting base plate is connected to a telescopic element, the bottom end of which is fixedly connected to the base.

7. A laser-based self-feedback additive control robot according to claim 1, characterized in that: The base is also provided with a recycling chamber, the bottom end of which extends to one side of the base, and a recycling chamber door is hinged to one side of the base.

8. A laser-based self-feedback additive control robot according to claim 1, characterized in that: The laser-based self-feedback additive control robot also includes a cover disposed on the top of the base, and the baffle is part of the cover.

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