WO2019114318A1

WO2019114318A1 - Powder laying state detection method and device for 3d printer

Info

Publication number: WO2019114318A1
Application number: PCT/CN2018/101799
Authority: WO
Inventors: 司志涛; 熊新; 郭帅; 乔凤雨
Original assignee: 广东科达洁能股份有限公司
Priority date: 2017-12-13
Filing date: 2018-08-22
Publication date: 2019-06-20
Also published as: CN109910299B; CN109910299A

Abstract

A powder laying state detection method and device for a 3D printer, the method comprising: detecting a powder laying state of the current printing layer by means of a light curtain (10) (S101), the light curtain (10) being parallel to a printing plane of the 3D printer; determining, according to the powder laying state of the current printing layer, whether the current printing layer is normal (S102); and if the current printing layer is normal, printing the next layer, and if the current printing layer is abnormal, generating, according to the type of the abnormality, a control signal for correspondingly adjusting the current printing layer (S103). The method realizes monitoring of the printing state of each layer of powder of the 3D printer and can timely discover and process a printing layer with abnormal powder laying, thus ensuring the quality of printed products.

Description

Method and device for detecting powdering state of 3D printer

Technical field

The present invention relates to the field of 3D printer technology, and in particular, to a method and apparatus for detecting a powdering state of a 3D printer.

Background technique

3D printing technology, which is a kind of rapid prototyping technology, is a digital model file based on the use of powdered metal or plastic bonding materials to build objects by layer-by-layer stacking. .

In the aspect of powder laying, the existing 3D printing technology mainly ensures the uniformity of powder laying by the movement precision of the lifting mechanism and the machining precision of the scraping mechanism. This method requires high movement control of the lifting mechanism and the machining accuracy of the flattening mechanism.

However, by improving the lifting mechanism and the flattening mechanism, the problem of uneven powder spreading during 3D printing cannot be completely avoided. In the case of uneven spreading, if it is not corrected in time, it will seriously affect the quality of printed products.

Summary of the invention

The invention provides a method and a device for detecting the powdering state of a 3D printer, so as to realize monitoring of the printing state of each layer of powder of the 3D printer, timely discovering and processing the printing layer with abnormal powdering, and ensuring the quality of the printed product.

In a first aspect, the present invention provides a method for detecting a powdering state of a 3D printer, comprising:

Measuring a powdering state of a current printing layer by a light curtain, wherein the light curtain is parallel to a printing plane of the 3D printer;

According to the powdering state of the current printing layer, it is determined whether the current printing layer is normal; if it is normal, the next layer is printed; if abnormal, a control signal for correspondingly adjusting the current printing layer is generated according to the type of the abnormality.

Optionally, the measuring the powdering state of the current printing layer by using the light curtain comprises:

Controlling the light curtain to move downward from the height position of the adjacent previous print layer until the light curtain is received at the receiving end of the light curtain;

The distance moved by the light curtain is recorded, and the light curtain received at the receiving end of the light curtain is analyzed.

Optionally, the determining whether the current printing layer is normal according to the polling state of the current printing layer includes:

When the distance moved by the light curtain is equal to a preset threshold, and the light curtain received by the light curtain receiving end is complete, it is determined that the current printing layer is normal;

When the distance moved by the light curtain is not equal to the preset threshold, or the light curtain received by the light curtain receiving end is incomplete, the current printing layer is determined to be abnormal.

Optionally, the adjusting the current printing layer according to the type of the abnormality, including:

When the distance moved by the light curtain is greater than a preset threshold, and the light curtain received by the light curtain receiving end is complete, the first difference between the moving distance of the light curtain and the preset threshold is obtained, and the current printing layer is eradicated a layer of powder equal to the thickness of the first difference;

When the distance moved by the light curtain is less than a preset threshold, and the light curtain received by the light curtain receiving end is complete, the second difference between the preset threshold and the light curtain moving distance is acquired, and the current printing layer is added. a layer of powder equal to the thickness of the second difference;

When the light curtain received at the receiving end of the light curtain is incomplete, the powder printed by the current printing layer is eradicated; and the current layer is reprinted according to the preset powder thickness.

In a second aspect, the present invention provides a powdering state detecting device for a 3D printer, comprising:

a laser thickness gauge for measuring a powdering state of a current printing layer by a light curtain, wherein the light curtain is parallel to a printing plane of the 3D printer;

a processor, configured to determine whether the current printing layer is normal according to the powdering state of the current printing layer; if normal, print the next layer; if abnormal, generate corresponding adjustments to the current printing layer according to the type of the abnormality control signal.

Optionally, the laser thickness gauge is specifically configured to:

Controlling the light curtain to move downward from the height position of the adjacent previous print layer until it stops when the light curtain receiving end receives the light curtain;

Optionally, the laser thickness gauge comprises: a laser emitter, a laser sensor, a light curtain analyzer;

The laser emitter is located at one side of a printing plane of the 3D printer for emitting a light curtain; wherein a height of the light curtain emitted by the laser emitter is adjustable, or a height of the laser emitter is adjustable;

The laser sensor is located on the other side of the printing plane of the 3D printer, for receiving a light curtain emitted by the laser emitter, and transmitting the received light curtain to the processor;

The light curtain analyzer is configured to record a distance moved by the light curtain, and analyze the light curtain received by the laser sensor to obtain a powder coating state of the current printing layer.

Optionally, the processor is specifically configured to:

Optionally, it also includes:

a powder spreading assembly for performing a powder feeding, a powdering, a smoothing operation, or a dusting operation according to a control signal sent by the processor;

a lifting assembly for controlling the height of the dusting assembly and/or the printing assembly according to a control signal sent by the processor;

The printer control board is configured to generate a corresponding start print signal or pause the print signal according to the control signal sent by the processor, and send the start print signal or the pause print signal to the print component;

a printing component for performing a printing operation according to a startup print signal sent by the printer control main board; or suspending a current printing operation according to a pause printing signal sent by the printer control main board.

Optionally, the processor is specifically configured to:

When the distance moved by the light curtain is greater than a preset threshold, and the light curtain received by the light curtain receiving end is complete, the first difference between the moving distance of the light curtain and the preset threshold is obtained, and the dusting component is currently Removing a layer of powder equal to the thickness of the first difference on the printing layer;

When the distance moved by the light curtain is less than a preset threshold, and the light curtain received by the light curtain receiving end is complete, a second difference between the preset threshold and the moving distance of the light curtain is obtained, and the dusting component is currently Adding a layer of powder equal to the thickness of the second difference on the printing layer;

When the light curtain received at the receiving end of the light curtain is incomplete, the powder printed by the current printing layer is removed by the powder spreading component; and the current layer is reprinted according to the preset powder thickness.

The method and device for detecting the powdering state of the 3D printer provided by the invention, the filming state of the current printing layer is measured by the light curtain, and the current printing layer is judged to be normal according to the powdering state of the current printing layer; if it is normal, the printing is performed. One layer; if abnormal, a control signal for correspondingly adjusting the current printing layer is generated according to the type of the abnormality. Thereby, the printing state of each layer of powder of the 3D printer is monitored, and the printing layer with abnormal powdering is detected and processed in time to ensure the quality of the printed product.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description of the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a top plan view of a 3D printer provided by the present invention;

2 is a flowchart of a method for detecting a powder spreading state of a 3D printer according to Embodiment 1 of the present invention;

3 is a schematic structural diagram of a powder spreading state detecting device of a 3D printer according to Embodiment 1 of the present invention;

4 is a top plan view of a powder discharging state detecting device of a 3D printer according to Embodiment 1 of the present invention;

In the picture:

1-laying assembly;

2-lift assembly;

3-printing component;

4- powder box;

5-print control board;

6-programmable logic controller PLC;

7-RS485 bus;

8-servo motor;

9-laser sensor;

10-light curtain;

11-laser transmitter.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The terms "first", "second", "third", "fourth", etc. (if present) in the specification and claims of the present invention and the above figures are used to distinguish similar objects without being used for Describe a specific order or order. It is to be understood that the data so used may be interchanged as appropriate, such that the embodiments of the invention described herein can be implemented, for example, in a sequence other than those illustrated or described herein. In addition, the terms "comprises" and "comprises" and "the" and "the" are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to Those steps or units may include other steps or units not explicitly listed or inherent to such processes, methods, products or devices.

The technical solutions of the present invention will be described in detail below with specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in some embodiments.

In the following, some of the terms in this application are explained so as to be understood by those skilled in the art:

1) 3D printing technology, which is a kind of rapid prototyping technology. It is a digital model file based on the use of powdered metal or plastic bonding materials to build objects by layer-by-layer stacking. Technology (ie "stacking method").

2) Programmable Logic Controller (PLC), which uses a type of programmable memory for storing programs internally, performing user-oriented instructions such as logic operations, sequence control, timing, counting, and arithmetic operations. And control various types of machinery or production processes through digital or analog inputs/outputs.

3) RS485 communication interface refers to the use of differential signal negative logic for data communication, where +2V ~ +6V means "0", -6V ~ -2V means "1". RS485 has two-wire and four-wire two-wire, four-wire system is full-duplex communication, and two-wire system is half-duplex communication.

The method for detecting the powdering state of the 3D printer provided by the present invention can be applied to an existing 3D printer using powder printing. 1 is a top view of a 3D printer provided by the present invention, as shown in FIG. 1, comprising: a powder spreading assembly 1, a lifting assembly 2, a printing assembly 3, and a powder box 4; the lifting assembly 2 controls the height of the powder box 4. When the preset height is reached, the powder spreading assembly 1 lays the powder in the powder box 4 on the current layer of the workpiece, and finally the printing of the current layer is completed by the printing unit 3. The 3D printer in Fig. 1 mainly ensures the uniformity of the powder laying by the movement precision of the lifting mechanism (lifting assembly 2) and the machining precision of the flattening mechanism. This method requires high movement control of the lifting mechanism and the machining accuracy of the flattening mechanism. However, by improving the lifting mechanism and the flattening mechanism, the problem of uneven powder spreading during 3D printing cannot be avoided. In the case of uneven spreading, if it is not corrected in time, it will seriously affect the quality of printed products.

The method for detecting the powdering state of the 3D printer provided by the present invention aims to solve the above technical problems of the prior art.

The technical solutions of the present invention and how the technical solutions of the present application solve the above technical problems will be described in detail below with reference to specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in some embodiments. Embodiments of the present invention will be described below with reference to the accompanying drawings.

2 is a flowchart of a method for detecting a powdering state of a 3D printer according to Embodiment 1 of the present invention. As shown in FIG. 2, the method in this embodiment may include:

S101. Measure the powdering state of the current printing layer by using a light curtain.

In this embodiment, the light curtain is parallel to the printing plane of the 3D printer, and the current printing layer is scanned by the light curtain to obtain a powdering state of the current printing layer.

Optionally, the light curtain can be moved downward from the height position of the adjacent previous printing layer until the light curtain is received at the light curtain receiving end; the distance of the light curtain movement is recorded, and the light curtain is analyzed The light curtain received at the receiving end.

S102: Determine whether the current printing layer is normal according to the powdering state of the current printing layer; if yes, execute step S104; if abnormal, perform step S103.

In this embodiment, the powdering state of the current printing layer can be determined according to the integrity of the light curtain received by the receiving end of the light curtain and the distance moved by the light curtain.

Optionally, when the distance moved by the light curtain is equal to a preset threshold, and the light curtain received by the light curtain receiving end is complete, determining that the current printing layer is normal;

S103. Generate a control signal for performing corresponding adjustment on the current printing layer according to the type of the abnormality.

In this embodiment, the abnormal type of the current printing layer is determined according to the distance moved by the light curtain and the integrity of the light curtain received by the light curtain receiving end. The abnormality type includes: the printing layer is too thick, the printing layer is too thin, and the printing layer is uneven. According to the type of the abnormality, a corresponding control signal is generated, and the control signal is sent to the printing component of the 3D printer.

Optionally, when the distance moved by the light curtain is greater than a preset threshold, and the light curtain received by the light curtain receiving end is complete, obtaining a first difference between the moving distance of the light curtain and the preset threshold, currently Removing a layer of powder equal to the thickness of the first difference on the printing layer;

S104, print the next layer.

In this embodiment, the powder coating state of the current printing layer is measured by the light curtain, and whether the current printing layer is normal according to the powdering state of the current printing layer; if normal, the next layer is printed; if abnormal, according to the type of the abnormality A control signal is generated that adjusts the current print layer accordingly. Thereby, the printing state of each layer of powder of the 3D printer is monitored, and the printing layer with abnormal powdering is detected and processed in time to ensure the quality of the printed product.

FIG. 3 is a schematic structural diagram of a powder-laying state detecting apparatus for a 3D printer according to Embodiment 1 of the present invention. As shown in FIG. 3, the apparatus in this embodiment may include:

a laser thickness gauge 20 for measuring a powdering state of a current printing layer by a light curtain, wherein the light curtain is parallel to a printing plane of the 3D printer;

The processor 30 is configured to determine whether the current printing layer is normal according to the powdering state of the current printing layer; if normal, print the next layer; if abnormal, generate corresponding adjustments to the current printing layer according to the type of the abnormality. Control signal.

The processor in this embodiment may be a programmable logic controller PLC, a microprocessor, or a single chip microcomputer. Specifically, in the embodiment, the programmable logic controller PLC is taken as an example for description, and the PLC can perform data communication with each component of the 3D printer through the RS485 bus.

Optionally, the laser thickness gauge 20 is specifically configured to:

Optionally, the processor 30 is specifically configured to:

Optionally, the processor 30 is further configured to:

In this embodiment, the light curtain emitted by the laser thickness gauge 20 is used to measure the powdering state of the current printing layer, and according to the powdering state of the current printing layer, it is determined whether the current printing layer is normal; if normal, the next layer is printed; If the abnormality is generated, a control signal for correspondingly adjusting the current print layer is generated according to the type of the abnormality. Thereby, the printing state of each layer of powder of the 3D printer is monitored, and the printing layer with abnormal powdering is detected and processed in time to ensure the quality of the printed product.

4 is a top view of a powder-laying state detecting device for a 3D printer according to Embodiment 1 of the present invention. As shown in FIG. 4, the device in this embodiment includes: a powder-spreading component 1, a lifting component 2, a printing component 3, and a powder body. Box 4, printer control board 5, laser thickness gauge, programmable logic controller PLC 6, RS485 bus 7, servo motor 8; wherein: the programmable logic controller PLC 6 through the RS485 bus 7 and the powder coating component 1, The lifting unit 2, the printing unit 3, and the printer control board 5 are electrically connected.

In one embodiment, the laser thickness gauge comprises: a laser emitter 11, a laser sensor 9, a light curtain analyzer; the laser emitter 11 is located on one side of a printing plane of the 3D printer, A light curtain is emitted; wherein the height of the light curtain emitted by the laser emitter 11 is adjustable, or the height of the laser emitter 11 is adjustable. The laser sensor 9 is located on the other side of the printing plane of the 3D printer for receiving a light curtain emitted by the laser emitter 11 and transmitting the received light curtain to the processor. The light curtain analyzer is configured to record a distance moved by the light curtain, and analyze the light curtain received by the laser sensor to obtain a powder coating state of the current printing layer.

The powder spreading assembly 1 is configured to perform a powder feeding, a powdering, a flattening operation, or a dusting operation according to a control signal sent by the processor. The lifting assembly 2 is configured to control the height of the powder discharging assembly and/or the printing assembly according to a control signal sent by the processor. The printer control board 5 is configured to generate a corresponding start print signal or pause the print signal according to the control signal sent by the processor, and send the start print signal or the pause print signal to the print component. The printing component 3 is configured to perform a printing operation according to the startup printing signal sent by the printer controlling the main board; or suspend the current printing operation according to the pause printing signal sent by the printer controlling the main board.

Optionally, the programmable logic controller PLC 6 may also store the detected thickness data of each print layer to facilitate analysis of the printing process to ensure print quality of each layer.

In this embodiment, the programmable logic controller PLC and the laser thickness gauge are combined to realize the detection of the powder layer state of each printing layer, and the degree of automation is high, and the abnormal state of the printing layer can be found in time, and the abnormal printed layer is performed. Finishing, which improves the print quality of the product.

In the description of the present invention, it is to be understood that the terms "center", "length", "width", "thickness", "top", "bottom", "upper", "lower", " Left or right, right, front, back, vertical, horizontal, inner, outer, axial, circumferential, etc. The orientation or positional relationship shown in the drawings is merely for the convenience of the description of the present invention and the description of the present invention, and is not intended to indicate or imply that the position or the original is to have a specific orientation, a specific configuration and operation, and therefore cannot be understood as a Limitations of the invention.

In the present invention, the terms "installation", "connected", "connected", "fixed" and the like should be understood broadly, and may be, for example, a fixed connection or a detachable connection, or It can be a mechanical connection, it can be a mechanical connection, or it can be electrically connected or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, which can make the internal connection of two components or the interaction of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A method for detecting a powdering state of a 3D printer, comprising:

Measuring a powdering state of a current printing layer by a light curtain, wherein the light curtain is parallel to a printing plane of the 3D printer;

According to the powdering state of the current printing layer, it is determined whether the current printing layer is normal; if it is normal, the next layer is printed; if abnormal, a control signal for correspondingly adjusting the current printing layer is generated according to the type of the abnormality.
The method according to claim 1, wherein the measuring the powdering state of the current printing layer by the light curtain comprises:

Controlling the light curtain to move downward from the height position of the adjacent previous print layer until it stops when the light curtain receiving end receives the light curtain;

The distance moved by the light curtain is recorded, and the light curtain received at the receiving end of the light curtain is analyzed.
The method according to claim 2, wherein the determining whether the current printing layer is normal according to the powdering state of the current printing layer comprises:

When the distance moved by the light curtain is equal to a preset threshold, and the light curtain received by the light curtain receiving end is complete, it is determined that the current printing layer is normal;

When the distance moved by the light curtain is not equal to the preset threshold, or the light curtain received by the light curtain receiving end is incomplete, the current printing layer is determined to be abnormal.
The method according to any one of claims 1 to 3, wherein the adjusting the current printing layer according to the type of the abnormality comprises:

When the distance moved by the light curtain is greater than a preset threshold, and the light curtain received by the light curtain receiving end is complete, the first difference between the moving distance of the light curtain and the preset threshold is obtained, and the current printing layer is eradicated a layer of powder equal to the thickness of the first difference;

When the distance moved by the light curtain is less than a preset threshold, and the light curtain received by the light curtain receiving end is complete, the second difference between the preset threshold and the light curtain moving distance is acquired, and the current printing layer is added. a layer of powder equal to the thickness of the second difference;

When the light curtain received at the receiving end of the light curtain is incomplete, the powder printed by the current printing layer is eradicated; and the current layer is reprinted according to the preset powder thickness.
A powder-laying state detecting device for a 3D printer, comprising:

a laser thickness gauge for measuring a powder coating state of a current printing layer by a light curtain, wherein the light curtain is parallel to a printing plane of the 3D printer;

a processor, configured to determine whether the current printing layer is normal according to the powdering state of the current printing layer; if normal, print the next layer; if abnormal, generate corresponding adjustments to the current printing layer according to the type of the abnormality control signal.
The device according to claim 5, wherein the laser thickness gauge is specifically configured to:

Controlling the light curtain to move downward from the height position of the adjacent previous print layer until it stops when the light curtain receiving end receives the light curtain;

The distance moved by the light curtain is recorded, and the light curtain received at the receiving end of the light curtain is analyzed.
The device according to claim 5, wherein the laser thickness gauge comprises: a laser emitter, a laser sensor, a light curtain analyzer;

The laser emitter is located at one side of a printing plane of the 3D printer for emitting a light curtain; wherein a height of the light curtain emitted by the laser emitter is adjustable, or a height of the laser emitter is adjustable;

The laser sensor is located on the other side of the printing plane of the 3D printer, for receiving a light curtain emitted by the laser emitter, and transmitting the received light curtain to the processor;

The light curtain analyzer is configured to record a distance moved by the light curtain, and analyze the light curtain received by the laser sensor to obtain a powder coating state of the current printing layer.
The device according to claim 6, wherein the processor is specifically configured to:

When the distance moved by the light curtain is equal to a preset threshold, and the light curtain received by the light curtain receiving end is complete, it is determined that the current printing layer is normal;

When the distance moved by the light curtain is not equal to the preset threshold, or the light curtain received by the light curtain receiving end is incomplete, the current printing layer is determined to be abnormal.
The device according to claim 5, further comprising:

a powder spreading assembly for performing a powder feeding, a powdering, a smoothing operation, or a dusting operation according to a control signal sent by the processor;

a lifting assembly for controlling the height of the dusting assembly and/or the printing assembly according to a control signal sent by the processor;

The printer control board is configured to generate a corresponding start print signal or pause the print signal according to the control signal sent by the processor, and send the start print signal or the pause print signal to the print component;

a printing component for performing a printing operation according to a startup print signal sent by the printer control main board; or suspending a current printing operation according to a pause printing signal sent by the printer control main board.
The device according to any one of claims 5-9, wherein the processor is specifically configured to:

When the distance moved by the light curtain is greater than a preset threshold, and the light curtain received by the light curtain receiving end is complete, the first difference between the moving distance of the light curtain and the preset threshold is obtained, and the dusting component is currently Removing a layer of powder equal to the thickness of the first difference on the printing layer;

When the distance moved by the light curtain is less than a preset threshold, and the light curtain received by the light curtain receiving end is complete, a second difference between the preset threshold and the moving distance of the light curtain is obtained, and the dusting component is currently Adding a layer of powder equal to the thickness of the second difference on the printing layer;

When the light curtain received at the receiving end of the light curtain is incomplete, the powder printed by the current printing layer is removed by the powder spreading component; and the current layer is reprinted according to the preset powder thickness.