Acoustic monitoring assembly and additive manufacturing apparatus

Abstract

The application provides an acoustic monitoring assembly (20) and an additive manufacturing apparatus (10). An acoustic monitoring assembly (20) for an additive manufacturing apparatus (10) for manufacturing a three-dimensional object (104) by selectively scanning a powder material (P) layer by layer over a substrate (103) with an energy beam (EB), the acoustic monitoring assembly (20) comprising: a plurality of fiber optic acoustic sensors (201a, 201b, 201c, 201d) distributed in an array in space over the substrate (103), the acoustic sensors are used for capturing acoustic signals generated at the same position in the additive manufacturing process and modulating the acoustic signals into optical signals for transmission; the signal processing unit (202) is respectively connected with the plurality of optical fiber acoustic sensors (201a, 201b, 201c and 201d) through optical fibers and is used for receiving and processing optical signals transmitted by the plurality of optical fiber acoustic sensors (201a, 201b, 201c and 201d) so as to monitor the quality of additive manufacturing; and the warning indicator (203) is electrically connected with the signal processing unit (202) and is used for receiving the quality abnormal electric signals transmitted by the signal processing unit (202) so as to give an alarm for reminding.

Description

Technical Field

[0001] The present application relates generally to the field of additive manufacturing, and more particularly to acoustic monitoring assemblies and additive manufacturing apparatus. Background Art

[0002] In additive manufacturing, especially metal additive manufacturing that uses energy beams to melt or sinter powder materials to build three-dimensional objects layer by layer, quality monitoring in the additive manufacturing process has always been a key issue. Even small anomalies or deviations may lead to quality problems in the final product, resulting in forming failure. Traditional quality monitoring methods mainly rely on visual inspection, but this method is easily affected by lighting conditions and surface reflections, which limits its accuracy in real-time detection. In order to solve these problems, acoustic monitoring technology, as an emerging quality monitoring method, has gradually been introduced into the field of additive manufacturing. Acoustic monitoring technology can reflect the melting, cooling and solidification processes of materials in real time by capturing and analyzing the acoustic signals generated during the additive manufacturing process. These acoustic signals are formed by the propagation of sound waves generated during the interaction between the energy beam and the powder material, the phase change of the material, and the movement of the build platform. By accurately identifying and analyzing these acoustic signals, operators can adjust manufacturing parameters in a timely manner to ensure product quality and maximize manufacturing efficiency.

[0003] However, existing additive manufacturing acoustic monitoring technology has some limitations in the use of acoustic sensors. For example, existing acoustic sensors (such as microphones) have insufficient sensitivity, making it difficult to capture high-frequency and weak signal changes, are greatly affected by environmental noise interference, and the layout may not be able to effectively capture the changes in acoustic signals at each monitoring location at different time points. Utility Model Content

[0004] The purpose of this application is to provide an acoustic monitoring component and additive manufacturing equipment, which utilizes a highly sensitive fiber optic acoustic sensor to perform real-time monitoring of acoustic signals to improve the efficiency of acoustic monitoring.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0006] According to a first aspect of the present application, there is provided an acoustic monitoring component for an additive manufacturing device, wherein the additive manufacturing device is used to selectively scan powder materials layer by layer in a building area using an energy beam to manufacture a three-dimensional object, and the acoustic monitoring component comprises: a plurality of fiber optic acoustic sensors, wherein the plurality of fiber optic acoustic sensors are distributed in an array in a space above the building area, and are used to respectively capture acoustic signals generated by the same position during the additive manufacturing process and modulate them into optical signals for transmission; and a signal processing unit, wherein the signal processing unit is respectively connected to the plurality of fiber optic acoustic sensors via optical fibers, and is used to receive and process the optical signals transmitted by the plurality of fiber optic acoustic sensors to monitor the quality of additive manufacturing.

[0007] In a possible implementation, the plurality of fiber optic acoustic sensors are distributed in a linear array in the space above the building area.

[0008] In a possible implementation, the plurality of linear arrays of optical fiber acoustic sensors are distributed in a vertical direction of the additive manufacturing device.

[0009] In a possible implementation, the plurality of optical fiber acoustic sensors are distributed in a matrix array or an irregular array in the space above the building area.

[0010] In a possible implementation, the acoustic monitoring assembly further includes a support member, the support member is disposed in the space above the building area, and the plurality of optical fiber acoustic sensors are disposed on the support member.

[0011] In one possible embodiment, the signal processing unit includes: a plurality of photodetectors, which are correspondingly connected to the plurality of fiber optic acoustic sensors via optical fibers, and are used to convert optical signals transmitted by the optical fibers into electrical signals; a microcontroller, which is electrically connected to the plurality of photodetectors, and is used to receive and process the electrical signals output by the plurality of photodetectors to monitor the quality of additive manufacturing, and output signals of abnormal quality to the alarm device.

[0012] In a possible implementation, the acoustic monitoring component (20) further includes an alarm (203), wherein the alarm (203) is electrically connected to the microcontroller (207) and is used to receive an electrical signal of abnormal quality transmitted by the microcontroller (207) to issue an alarm.

[0013] In a possible implementation, the fiber optic acoustic sensor includes a fiber Bragg grating.

[0014] According to a second aspect of the present application, there is provided an additive manufacturing device having the acoustic monitoring assembly described in any one of the first aspects.

[0015] In a possible implementation, the additive manufacturing equipment includes a forming chamber, and the plurality of fiber optic acoustic sensors are disposed in the forming chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0017] Figure 1 is a schematic diagram of the application of the acoustic monitoring component provided in the embodiment of the present application in the additive manufacturing equipment;

[0018] Figure 2 is a schematic diagram of the structure of a fiber Bragg grating provided in an embodiment of the present application;

[0019] Figure 3 (a), (b), (c) and (d) are schematic diagrams of different array distributions of optical fiber acoustic sensors provided in embodiments of the present application;

[0020] Figure 4 (a), (b), (c) and (d) are the supporting parts provided in the embodiment of the present application. Figure 3 Application diagram in ;

[0021] Figure 5 is a schematic diagram of the structure of the additive manufacturing device provided in the embodiment of the present application;

[0022] Figure 6 is a schematic diagram of the circuit structure of the acoustic monitoring component provided in an embodiment of the present application;

[0023] Figure 7 It is a schematic diagram of the structure of the comparison circuit provided in the embodiment of the present application. DETAILED DESCRIPTION

[0024] The exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0025] The term "energy beam" used herein refers to various forms of energy focused into a beam, which is used to manufacture three-dimensional objects in the additive manufacturing process. It is preferably a laser beam, but can also be an electron beam, ion beam, plasma beam, etc.

[0026] "Additive manufacturing" in this article refers to the manufacturing method of building three-dimensional objects by stacking powder materials layer by layer, also known as "layer-by-layer manufacturing" or "3D (three-dimensional) printing". It covers various types of additive manufacturing that use energy beams to sinter / melt materials, such as selective laser sintering (SLS) and selective laser melting (SLM).

[0027] The "powder material" in this article refers to the raw materials used to manufacture three-dimensional objects. In terms of physical structure, it mainly refers to powder particles, which can have different shapes, sizes and particle sizes. The "powder material" in this article is preferably made of metal, such as stainless steel, copper, titanium alloy, aluminum alloy, etc. In addition, ceramics, plastics and some composite powder materials can also be used to construct three-dimensional objects.

[0028] Figure 1 Schematic diagram of the application of the acoustic monitoring component provided in the embodiment of the present application in the additive manufacturing device. The present embodiment provides an acoustic monitoring component 20 for the additive manufacturing device 10, and the acoustic monitoring component 20 is a part of the additive manufacturing device 10. The additive manufacturing device 10 generally utilizes an optical scanning system composed of at least an energy beam emitter 101 and a beam deflector 102 to selectively generate an energy beam EB in a building area formed above the substrate 103 according to a preset path, that is, to scan the surface of the powder bed PB, and form a corresponding layer of solid structure by sintering / melting the newly laid powder material P on the surface of the powder bed PB, and finally form the desired three-dimensional object 104 by laying the powder material P layer by layer and scanning.

[0029] It should be understood that the formation process of the solid structure is also the formation and solidification process of the molten pool MP. When the energy beam EB acts on the surface of the powder material P, the surface of the material is affected by the high-energy heat source, and the temperature rises rapidly, causing the material to melt to form a liquid molten pool MP composed of molten metal. As the temperature of the molten pool MP gradually decreases until it is lower than the solidification temperature of the material, the liquid metal solidifies into a solid material; during the solidification process, the material molecules are rearranged to form a crystal structure, and finally a solid structure with a certain shape and size is formed. During the formation and solidification process of the molten pool MP, there are strong physical and chemical changes such as heat conduction, heat radiation, heat convection, solidification, and phase change inside the molten pool MP. The state of the molten pool MP directly affects the quality and consistency of the formed product. Therefore, real-time monitoring of the state of the molten pool MP is the key to controlling the additive manufacturing process. According to the state of the molten pool MP, defects and problems in the printing process can be discovered in time, and the failure of the three-dimensional object 104 can be effectively avoided.

[0030] The acoustic monitoring assembly 20 provided in the present application can provide important information about the state of the molten pool by capturing acoustic signals during the molten pool formation and solidification process. This information can be used to adjust manufacturing parameters to ensure the forming quality of the three-dimensional object 104.

[0031] [Overview of Acoustic Monitoring Components]

[0032] Reference Figure 1 The acoustic monitoring assembly 20 of the embodiment of the present application includes optical fiber acoustic sensors 201a, 201b, 201c, 201d (in actual application, the number may be less or more), a signal processing unit 202, and an alarm 203. The optical fiber acoustic sensors 201a-201d are arrayed in the space above the substrate 103, and are respectively connected to the input end of the signal processing unit 202 through optical fibers, and the alarm 203 is connected to the output end of the signal processing unit 202. The optical fiber acoustic sensors 201a-201d can respectively capture the acoustic signals generated by the same position in the additive manufacturing process and modulate them into optical signals to transmit to the signal processing unit 202. The signal processing unit 202 receives and processes the optical signals transmitted by the optical fiber acoustic sensors 201a-201d, so as to output an electrical signal of quality abnormality to the alarm 203 when the quality abnormality of the additive manufacturing is detected according to the optical signal (such as poor formation of the molten pool MP, uneven melting of the powder material P, etc.), so as to prompt the alarm 203 to alarm. The alarm device 203 may be a device such as a buzzer or an LED light, which is used to warn the operator of potential quality problems so that adjustments can be made in time.

[0033] Fiber optic acoustic sensors use optical principles to capture acoustic signals, have strong resistance to electromagnetic interference, and have high sensitivity. They can capture tiny changes in acoustic signals, and have relatively low noise levels. They perform well in high-precision acoustic monitoring applications.

[0034] Figure 2: is a schematic diagram of the structure of the fiber Bragg grating provided in the embodiment of the present application. In some embodiments of the present application, the fiber acoustic sensor 201a-201d can be a fiber Bragg grating (FBG). The structure of the fiber Bragg grating is an outer cladding, a fiber cladding, a fiber core, and a grating group arranged on the fiber core from the outside to the inside. The grating group is composed of a series of refractive index modulation units, and the distance between these units is called the grating period (Λ). When the grating period is about half the wavelength of the incident light, light of a specific wavelength will be reflected in the optical fiber to form a Bragg reflection. Specifically, FBG is formed by introducing a periodic refractive index change in the optical fiber. This structure can reflect light of a specific wavelength, and when the external stress or temperature changes, the reflected wavelength will also change. Therefore, FBG can be used to monitor acoustic signals in real time, and these signals can be associated with the state of the molten pool and the change of material properties in the additive manufacturing process. FBG is very sensitive to small stress and temperature changes, making it suitable for fine acoustic monitoring. FBG sensors are small in size and light in weight, and can be easily integrated into additive manufacturing equipment without affecting the manufacturing process. By integrating multiple FBGs on the same optical fiber, multi-point monitoring can be achieved.

[0035] This application uses an acoustic monitoring component of FBG sensors, which only requires one set. The spatial array setting can realize the high-precision positioning scanning path of the entire spatial format in the forming chamber, and detect the printing situation in real time in all directions; whether there are multiple laser systems is completely unrestricted, and compared with similar detection equipment such as high-speed cameras, it has obvious advantages, low cost and good effect. In addition, the acoustic monitoring component using FBG sensors can effectively realize real-time monitoring of the molten pool state. Through real-time monitoring and analysis of acoustic characteristics, the construction quality of the molten pool can be accurately judged, and defects and problems in the printing process can be discovered in time, thereby improving the control accuracy and yield rate of the additive manufacturing process.

[0036] In addition to FBG, in possible implementations, the fiber optic acoustic sensor can also be a Fabry-Perot interferometer sensor that uses the interference effect of a multilayer film to detect acoustic waves, a fiber optic microbend sensor that senses changes in acoustic wave signals through tiny bends in the optical fiber, etc.

[0037] In addition, the energy beam EB can not only excite the electrons of atoms and molecules on the surface of the powder material P, but also transfer energetic photons to metal atoms, causing them to leave the crystal structure. These excited, high-energy electrons and ions gradually form plasma through complex electromagnetic interactions. Monitoring the characteristics of these plasmas (such as frequency) can help understand the state of the molten pool MP and its dynamic changes.

[0038] Specifically, the fiber optic acoustic sensor can use FBG to measure the frequency of the plasma. In addition to FBG, the fiber optic acoustic sensor can use a fiber optic interferometer sensor to detect the frequency in the plasma. In some possible implementations, a piezoelectric sensor or an ultrasonic sensor can also be used to measure the ion body frequency in the plasma. These sensors can be selected alone or used in conjunction with the fiber optic acoustic sensor.

[0039] [Layout of fiber optic acoustic sensor]

[0040] Figure 3 2 is a schematic diagram of different array distributions of optical fiber acoustic sensors provided in the embodiments of the present application. The optical fiber acoustic sensors 201a-201d of the embodiments of the present application are distributed in the space above the substrate 103 in the following arrays:

[0041] Vertical Linear Array Distribution

[0042] like Figure 3 As shown in (a), the optical fiber acoustic sensors 201a-201d are distributed in a vertical linear array in the space above the substrate 103. In the vertical linear array, the optical fiber acoustic sensors 201a-201d can be arranged equidistantly along the vertical direction.

[0043] Horizontal Linear Array Distribution

[0044] like Figure 3 As shown in (b), the optical fiber acoustic sensors 201a-201d are arranged in a horizontal linear array in the space above the substrate 103. In the horizontal linear array, the optical fiber acoustic sensors 201a-201d can be evenly spaced along the horizontal axis, for example. This arrangement is suitable for monitoring the lateral acoustic changes on the surface of the substrate 103, and can effectively detect any abnormalities in the lateral extension process.

[0045] Matrix array distribution

[0046] like Figure 3 As shown in (c), the optical fiber acoustic sensors 201a-201d are distributed in a matrix array in the space above the substrate 103. In the matrix array, the optical fiber acoustic sensors 201a-201d are arranged in rows and columns. This two-dimensional distribution provides a more comprehensive acoustic monitoring capability, can cover a larger area, and is suitable for complex geometric shapes and manufacturing scenarios.

[0047] Irregular array distribution

[0048] like Figure 3As shown in (d), the optical fiber acoustic sensors 201a-201d are distributed in an irregular array in the space above the substrate 103. In the irregular array, the optical fiber acoustic sensors 201a-201d are arranged at non-fixed intervals. This arrangement is more flexible and can focus on monitoring specific areas according to specific needs to capture irregular acoustic signals.

[0049] It should be understood that, through the above-mentioned spatial array method, the distance between the fiber optic acoustic sensors 201a-201d is known, which makes it possible to locate the position of the energy beam EB based on the time difference of the acoustic signal. For example, when the fiber optic acoustic sensors 201a-201d are distributed in a vertical linear array, the scanning position of the energy beam EB on the substrate 103 can be determined with high precision. The signal received by each sensor will have a slight time difference (after the sound wave is emitted, the time it arrives at each sensor is slightly different, depending on the difference in the path length of the sound wave propagation). By analyzing these time differences, the specific position of the sound source can be calculated. In addition, by combining the data of the scanning path, the movement trajectory of the energy beam EB can be further tracked. By recording the time difference of the acoustic signal at different time points, the position and movement direction of the energy beam EB can be updated in real time, thereby monitoring its movement in three-dimensional space. This positioning method has a high-frequency information capture capability, which can monitor the status of each position in real time during the additive manufacturing process, capture higher-resolution quality information, and thus improve the accuracy and consistency of the printing process.

[0050] Figure 4 The supporting member provided in the embodiment of the present application is Figure 3 See the application diagram in Figure 4 The acoustic monitoring assembly 20 also includes a support 204, which is disposed in the space above the substrate 103, and the optical fiber acoustic sensors 201a-201d are disposed on the support 204 to effectively capture the acoustic signals generated during the additive manufacturing process. The support 204 refers to a fixed structure that can fix the optical fiber acoustic sensors 201a-201d in the additive manufacturing equipment, especially in the forming chamber of the additive manufacturing equipment, for example, it can be one or more combined rods, and the optical fiber acoustic sensors 201a-201d are mounted on the rods, and one end of the rods is fixed in the forming chamber. The fixing method can be bolts or other common mechanical connection methods to ensure the precise positioning and signal acquisition of the sensor.

[0051] Figure 5 Schematic diagram of the structure of the additive manufacturing equipment provided in the embodiment of the present application. Figure 5 The fiber optic acoustic sensors 201a-201d can also be directly fixed on the inner wall of the forming chamber 107 without relying on the support member 204. For example, the fiber optic acoustic sensors 201a-201d can be specifically installed on the inner wall of the forming chamber 107 on the side adjacent to the forming cylinder 109.

[0052] [Circuit structure of acoustic monitoring component]

[0053] Figure 6 : is a schematic diagram of the circuit structure of the acoustic monitoring component provided in the embodiment of the present application. In the embodiment of the present application, the optical fiber acoustic sensors 201a-201d are respectively connected to the input end of the signal processing unit 202 through optical fibers, and the alarm 203 is connected to the output end of the signal processing unit 202. The signal processing unit 202 includes photodetectors 205a-205d and a microcontroller 207. The output ends of the optical fiber acoustic sensors 201a-201d are correspondingly connected to the input ends of the photodetectors 205a-205d through optical fibers, and the output ends of the photodetectors 205a-205d are correspondingly electrically connected to four of the input ends of the microcontroller 208, and the output end of the microcontroller 208 is electrically connected to the input end of the alarm 203.

[0054] The optical fiber acoustic sensors 201a-201d capture the sound fluctuations in the surrounding environment and convert the captured sound signals into optical signals for output. The output optical signals are transmitted to the photodetectors 205a-205d via optical fibers. These detectors can convert the received optical signals into electrical signals, thus providing a basis for subsequent signal processing. The electrical signals output by the photodetectors 205a-205d are transmitted to the microcontroller 207 via electrical connections. The microcontroller 207 receives the electrical signals from the photodetectors 205a-205d and analyzes and processes the signals. The main function of the microcontroller 207 is to monitor the quality of the additive manufacturing process. When an abnormality is detected, a corresponding quality abnormality signal is generated. This signal is transmitted to the alarm 203 via an electrical connection. When an abnormality is detected, the alarm 203 will sound an alarm to prompt the operator to handle it in time.

[0055] Figure 7It is a structural diagram of the comparison circuit provided in the embodiment of the present application. In some embodiments, the microcontroller 207 can realize the abnormal monitoring function of additive manufacturing through a comparison circuit (voltage comparator). Taking the monitoring of the molten pool as an example, for example, a fixed reference voltage can be provided as a reference benchmark for the comparison circuit. This benchmark can be set according to the characteristics of the acoustic signal under normal operating conditions (according to multiple experiments and data analysis, a reference voltage that can accurately represent the normal molten pool state is set), such as a preset amplitude and frequency range, which is used to indicate a good molten pool state. The microcontroller 207 compares the voltage of the acoustic signal obtained in real time with the reference voltage through a voltage comparator. When the input signal exceeds the preset reference range or threshold, the voltage comparator will generate a logic state change or level change. When the microcontroller 207 detects an acoustic signal that exceeds the normal range, it will trigger the output of the abnormal signal. After the abnormal signal is output, the alarm 203 will receive the signal and issue an alarm to prompt the operator that there is an abnormal molten pool state.

[0056] Reference Figure 7 , exemplarily, Vin is the input voltage signal, connected to the positive input terminal (+) of the voltage comparator; a reference voltage is generated by a voltage divider (composed of R1 and R2), which is connected to the negative input terminal (-) of the voltage comparator. The output terminal (Vout) of the voltage comparator is connected to one end of the current limiting resistor R3, the positive pole (long leg) of the LED (warning device 203) is connected to the other end of the current limiting resistor R3, and the negative pole (short leg) of the LED is connected to the ground (GND). Specifically, when Vin exceeds the reference voltage, the output (Vout) of the voltage comparator becomes a high level (close to +V), and the current passes through the current limiting resistor R3 and the LED, lighting up the LED. When Vin is lower than the reference voltage, the output (Vout) of the comparator becomes a low level (close to -V or 0V), and the LED goes out because there is not enough voltage to drive it.

[0057] In some possible implementations, the microcontroller 207 can receive digital signals from the A / D converters 206a-206d and calculate the mean of the acoustic signal. For example, the microcontroller 207 accumulates all the digital signal values ​​received within a predetermined time window and records the number of signal samples entering the accumulator. Subsequently, the microcontroller 207 divides the accumulated signal value by the number of samples to obtain the mean of the acoustic signal within the time period for subsequent comparison and analysis. The microcontroller 207 compares the mean of the acoustic signal with a preset reference range or threshold through a comparator and a reference circuit. When the mean of the acoustic signal exceeds the normal range, the comparator generates an output of a logic state change or a level change. The microcontroller 207 monitors the output state of the comparator and triggers a corresponding warning when an abnormal signal is detected to remind the operator that the molten pool state is abnormal.

[0058] Continue to refer to Figure 6 In some embodiments, the fiber optic acoustic sensors 201a-201d are respectively connected to the input end of the signal processing unit 202 through optical fibers, and the alarm 203 is connected to the output end of the signal processing unit 202. The signal processing unit 202 includes photodetectors 205a-205d, A / D converters 206a-206d, a microcontroller 207, and a D / A converter 208. The output ends of the fiber optic acoustic sensors 201a-201d are correspondingly connected to the input ends of the photodetectors 205a-205d through optical fibers, the output ends of the photodetectors 205a-205d are correspondingly electrically connected to the input ends of the A / D converters 206a-206d, the output ends of the A / D converters 206a-206d are correspondingly electrically connected to the input end of the microcontroller 208, the output end of the microcontroller 208 is electrically connected to the input end of the D / A converter 208, and the output end of the D / A converter 208 is electrically connected to the input end of the alarm 203.

[0059] The optical fiber acoustic sensors 201a-201d capture the sound fluctuations in the surrounding environment and convert the captured sound signals into optical signals for output. The output optical signals are transmitted to the photodetectors 205a-205d via optical fibers. These detectors can convert the received optical signals into electrical signals, thereby providing a basis for subsequent signal processing. The electrical signals output by the photodetectors 205a-205d are transmitted to the A / D converters 206a-206d via electrical connections, and these converters convert analog signals into digital signals. The microcontroller 207 receives the digital signals from the A / D converters 206a-206d and analyzes and processes the signals. The main function of the microcontroller 207 is to monitor the quality of the additive manufacturing process. When an abnormality is detected, a corresponding quality abnormality signal is generated. Finally, the digital signal output by the microcontroller 207 is transmitted to the D / A converter 208, which converts it back into an analog signal. This signal is transmitted to the alarm 203 via an electrical connection. When an abnormality is detected, the alarm 203 will sound an alarm to prompt the operator to handle it in time. The microcontroller 207 here can realize the abnormality monitoring function of additive manufacturing through the processor and the memory (storing the standard acoustic signal). For example, after receiving the digital signal, the processor analyzes and processes the signal, compares the acoustic signal characteristics (such as amplitude, frequency, etc.) obtained in real time with the standard acoustic signal in the memory, and calculates the difference between the current acoustic signal and the standard signal to determine whether the quality of additive manufacturing is abnormal.

[0060] [Additive manufacturing equipment]

[0061] The additive manufacturing device 10 provided in the embodiment of the present application has the acoustic monitoring assembly 20 described in any of the above embodiments. Figure 5In addition to the energy beam emitter 101 and beam deflector 102 (such as a galvanometer) disclosed above, the optical scanning system of the additive manufacturing device 10 also has a collimator 105 and a focusing field lens 106. The energy beam generator 101 (such as a laser) generates a high-energy-density laser beam and collimates it through the collimator 105 to inject it into the galvanometer. The galvanometer consists of a group of reflectors that can control the irradiation direction and path of the laser beam and a motor for driving the deflection of the reflector. It can rotate quickly and accurately in different directions to control the irradiation position and angle of the laser beam; the focusing lens focuses the laser beam on the surface of the powder material to achieve sintering / melting of the powder material P.

[0062] The additive manufacturing device 10 also includes a forming cylinder 109 for constructing a three-dimensional object 104, at the bottom of which a lifting device 111 is provided, and the substrate 103 is disposed in the forming cylinder 109 and can move up and down along the inner wall of the forming cylinder 109 under the drive of the lifting device 111, so as to promote the layer-by-layer addition of powder material P to form a powder bed PB, so as to construct the desired three-dimensional object 104. It should be understood that in the 3D printing process, the thickness of each layer of the substrate 103 is the thickness of the next powder layer.

[0063] The additive manufacturing device 10 also includes a powder cylinder 108, which is arranged on one side of the forming cylinder 109. A lifting device 110 is arranged at the bottom of the powder cylinder 108. The powder cylinder 108 is used to store powder material P for 3D printing and can overflow powder under the drive of the lifting device 110 to accumulate on its top area, and then the powder spreading device 112 (scraper or roller) moves the powder material P accumulated in the top area of ​​the powder cylinder 108 to the substrate 103.

[0064] In addition, the additive manufacturing device 10 is also equipped with a computer control system for controlling the operation of each component. In addition to conventional component control, it can also include control of the acoustic monitoring component 20 of the present application, so as to ensure the smooth progress of the printing process and the stability of the printing quality. For example, the quality abnormality signal output by the signal processing unit can be directly fed back to the computer control system through the data interface. The computer control system automatically adjusts the printing parameters (such as laser power, scanning speed, powder supply, etc.) according to the quality abnormality signal to correct the abnormal situation. Through the control system, the alarm 203 is triggered to sound an alarm to notify the operator to check and handle the abnormality.

[0065] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and embodiments are to be regarded as exemplary only, and the present application is not limited to the precise structures described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof.

[0066] 10 Additive Manufacturing Equipment

[0067] 101 Energy Beam Launcher

[0068] 102 Beam Deflector

[0069] EB Energy Beam

[0070] PB powder bed

[0071] Powder Material

[0072] MP melt pool

[0073] 103 substrate

[0074] 104 Three-dimensional objects

[0075] 105 Collimator

[0076] 106 Focusing field lens

[0077] 107 Forming Chamber

[0078] 108 Powder cylinder

[0079] 109 Forming cylinder

[0080] 110, 111 lifting device

[0081] 112 Powder spreading device

[0082] 20 Acoustic Monitoring Components

[0083] 201a-201d Fiber Optic Acoustic Sensor

[0084] 202 Signal Processing Unit

[0085] 203 Warning Device

[0086] 204 Support

[0087] 205a-205d Photodetector

[0088] 206a-206d A / D Converter

[0089] 207 Microcontroller

[0090] 208 D / A converter.

Claims

1. An acoustic monitoring assembly (20) for an additive manufacturing device (10), the additive manufacturing device (10) being used to selectively scan a powder material (P) layer by layer in a building area using an energy beam (EB) to manufacture a three-dimensional object (104), the acoustic monitoring assembly (20) comprising: A plurality of optical fiber acoustic sensors (201a, 201b, 201c, 201d), wherein the plurality of optical fiber acoustic sensors (201a, 201b, 201c, 201d) are distributed in an array in the space above the building area, and are used to respectively capture acoustic signals generated at the same position during the additive manufacturing process and modulate them into optical signals for transmission; A signal processing unit (202), the signal processing unit (202) is connected to the multiple optical fiber acoustic sensors (201a, 201b, 201c, 201d) respectively through optical fibers, and is used to receive and process optical signals transmitted by the multiple optical fiber acoustic sensors (201a, 201b, 201c, 201d) to monitor the quality of additive manufacturing.

2. The acoustic monitoring assembly (20) according to claim 1, wherein the plurality of fiber optic acoustic sensors (201a, 201b, 201c, 201d) are distributed in a linear array in the space above the construction area.

3. The acoustic monitoring assembly (20) according to claim 2, wherein the plurality of optical fiber acoustic sensors (201a, 201b, 201c, 201d) are linearly arrayed and distributed in a vertical direction of the additive manufacturing device (10).

4. The acoustic monitoring assembly (20) according to claim 1, wherein the plurality of fiber optic acoustic sensors (201a, 201b, 201c, 201d) are distributed in a matrix array or an irregular array in the space above the construction area.

5. The acoustic monitoring assembly (20) according to claim 1, wherein the acoustic monitoring assembly (20) further comprises a support member (204), wherein the support member (204) is disposed in a space above the building area, and the plurality of optical fiber acoustic sensors (201a, 201b, 201c, 201d) are disposed on the support member (204).

6. The acoustic monitoring assembly (20) of claim 1, wherein the signal processing unit (202) comprises: A plurality of photoelectric detectors (205a, 205b, 205c, 205d), wherein the plurality of photoelectric detectors (205a, 205b, 205c, 205d) are correspondingly connected to the plurality of optical fiber acoustic sensors (201a, 201b, 201c, 201d) via optical fibers, and are used to convert optical signals transmitted by the optical fibers into electrical signals; A microcontroller (207), the microcontroller (207) being electrically connected to the plurality of photodetectors (205a, 205b, 205c, 205d), and being used for receiving and processing the electrical signals output by the plurality of photodetectors (205a, 205b, 205c, 205d) to monitor the quality of additive manufacturing.

7. The acoustic monitoring component (20) according to claim 6, wherein the acoustic monitoring component (20) further comprises an alarm (203), wherein the alarm (203) is electrically connected to the microcontroller (207) and is used for receiving an electrical signal of abnormal quality transmitted by the microcontroller (207) to issue an alarm.

8. The acoustic monitoring assembly (20) according to any one of claims 1 to 7, wherein the fiber optic acoustic sensor (201a, 201b, 201c, 201d) comprises a fiber Bragg grating.

9. An additive manufacturing device (10) having the acoustic monitoring assembly (20) according to any one of claims 1 to 8.

10. The additive manufacturing device (10) according to claim 9, wherein the additive manufacturing device (10) comprises a forming chamber (107), and the plurality of fiber optic acoustic sensors (201a, 201b, 201c, 201d) are arranged in the forming chamber (107).

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