Wind speed uniformity adjusting control system for SLM metal additive equipment

Abstract

The utility model relates to the technical field of metal additive manufacturing, and provides a wind speed uniformity adjusting control system for SLM (Selective Laser Melting) metal additive equipment, which is characterized in that sensors are arranged at the positions of an air blowing port and an air suction port for wind speed detection, and pressure sensors are arranged in a printing cabin along the central axis direction of a wind field for pressure feedback; global wind field characteristics are captured, PID control is adopted to quickly respond to wind speed fluctuation, and the wind field pressure difference gradient is combined to realize quick and reliable regulation and control of wind field uniformity in a constraint manner; the problem that in the printing process of metal additive manufacturing equipment, wind speed fluctuation and attenuation of various wind field structures and interference of a uniform wind field in a printing cabin in the adjusting process affect the part forming quality is solved.

Description

Technical Field

[0001] This utility model relates to the field of metal additive manufacturing technology, and in particular to wind field uniformity technology, specifically to a wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment. Background Technology

[0002] Metal additive manufacturing equipment, especially selective laser melting (SLM) equipment, often generates spatter and fumes during the printing process. Spatter significantly affects the quality of the printed parts, while fumes can obstruct the laser lens, directly impacting the stability of the printing process. Therefore, SLM equipment design must incorporate a circulating airflow module (airflow structure) with symmetrically distributed air inlets and outlets within the forming chamber. This allows for stable flow of protective gas within the chamber, carrying away the generated spatter and fumes, reducing their impact on the metal deposition layer, and thus improving component quality.

[0003] With the continuous expansion of the metal additive manufacturing market, extensive research and development has been conducted on the air source and internal structure of SLM equipment to create a stable airflow field. This includes the design of multi-source ductwork and the design of rectifier channels for the blowing and suction structures, aiming to obtain airflow parallel to the printing plane within the forming chamber. However, it is difficult to guarantee the uniformity of air velocity and the balance of airflow intensity at the blower outlet through mechanical design alone. This is because traditional fan frequency converters mostly use fixed-frequency control. Coupled with the effects of long-term equipment operation, increased pressure difference in duct filter elements, and attenuation and fluctuation of air velocity, operators need to periodically adjust the fan frequency to achieve the desired air velocity based on the equipment's operating conditions. This frequent operation greatly increases the labor costs associated with the equipment, and the fluctuating air velocity also interferes with the uniform airflow field, affecting the quality of part forming. This also increases the research and development investment in mechanical structures (such as the design of multi-source ductwork and the design of rectifier channels for the blowing and suction structures).

[0004] Therefore, developing a wind speed adaptive dynamic adjustment method and device suitable for metal additive manufacturing equipment to facilitate uniform wind field is of great significance for improving printing quality, verifying the design effectiveness of the blowing and suction structure, and ensuring the quality of printed parts and the stability and consistency of the printing process. Utility Model Content

[0005] This invention aims to solve the problems of wind speed fluctuations and attenuation in various wind field structures during the printing process of metal additive manufacturing equipment, as well as the interference of the uniform wind field in the printing chamber during the adjustment process, which in turn affects the quality of part forming. It proposes a wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment. This system captures global wind field characteristics by placing sensors at the air outlet and air inlet for wind speed detection and pressure sensors arranged along the central axis of the wind field in the printing chamber for pressure feedback. PID control is used to quickly respond to wind speed fluctuations, and combined with the wind field pressure gradient, constraints are used to achieve rapid and reliable control of wind field uniformity. This solves the problems of wind speed fluctuations and attenuation in various wind field structures during the printing process of metal additive manufacturing equipment, as well as the interference of the uniform wind field in the printing chamber during the adjustment process, which in turn affects the quality of part forming.

[0006] According to a first aspect of the present invention, a wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment is provided, comprising:

[0007] A printed chamber, the interior of which defines a process cavity for additive manufacturing; the printed chamber has an air inlet for receiving gas and an air outlet opposite to the air inlet, creating a uniform air field between the air inlet and the air outlet.

[0008] The fan's output port is connected to the printing chamber via an air intake pipe;

[0009] A first anemometer and a second anemometer are respectively installed at the air inlet and air outlet of the printing chamber to measure the transverse wind speed V of the incoming air. 进 And the horizontal air velocity V at the outlet 出 And according to the inlet cross wind speed V 进 And the horizontal air velocity V at the outlet 出 Determine the equivalent wind speed V of the uniform wind field between the air outlet and the air inlet, V = (V 进 +V 出 ) / 2;

[0010] A front pressure sensor and a rear pressure sensor are respectively installed on both sides of the filter element in the air inlet duct between the blower and the air outlet of the printing chamber to detect the pressure difference ΔP of the air inlet filter element. filter ;

[0011] The control system is electrically connected to the fan, the first anemometer, the second anemometer, the front pressure sensor, and the rear pressure sensor, and operates based on the equivalent wind speed V and the preset ideal wind speed V. target The difference is fed into feedback control to control the operation of the wind turbine's frequency converter, so as to follow and compensate for wind field interference caused by wind speed fluctuations;

[0012] An alarm system is electrically connected to the control system, which is based on the detected pressure difference ΔP of the air inlet filter. filter Exceeding the preset threshold Pth An alarm notification was issued.

[0013] As an optional embodiment, both the first and second anemometers are bidirectional ultrasonic anemometers with an accuracy of ±0.05m / s.

[0014] As an optional embodiment, the control system employs a PI closed-loop feedback controller or a PID closed-loop feedback controller, based on the equivalent wind speed V and the preset ideal wind speed V0. target The difference is fed into feedback control.

[0015] As an optional embodiment, the alarm system includes an audible and visual alarm, and uses different alarm prompts to indicate the degree of filter clogging.

[0016] As an optional embodiment, the first anemometer, the second anemometer, the front pressure sensor, and the rear pressure sensor are all zeroed.

[0017] As an optional embodiment, inside the printed chamber, multiple equally spaced micro-differential pressure sensors are arranged along the central axis of the uniform wind field to monitor the wind field pressure and determine the real-time wind field pressure gradient ΔP accordingly. / Δx;

[0018] All of the micro differential pressure sensors are electrically connected to the control system.

[0019] As an optional embodiment, multiple micro differential pressure sensors are arranged at equal intervals of 10 mm.

[0020] As an optional embodiment, the control system is configured to receive sampled values ​​from multiple micro-differential pressure sensors at the same time, and determine the wind field pressure gradient ΔP based on the sampled values ​​from the micro-differential pressure sensors downstream and upstream of the wind field. / Δx:

[0021] ΔP / Δx=(px3-px1) / d

[0022] Where px3 and px1 represent the sampled values ​​of the differential pressure sensors downstream and upstream of the wind field, respectively, and d represents the distance between the differential pressure sensors downstream and upstream of the wind field.

[0023] As an optional embodiment, the control system is configured to adjust according to the wind field pressure difference gradient ΔP. / Δx controls the operation of the frequency converter of the wind turbine.

[0024] As an optional embodiment, the control system is an embedded control system.

[0025] The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment, as designed in this utility model, achieves refined control of the airflow state within the SLM process cavity through multi-sensor fusion and closed-loop feedback mechanisms, thereby achieving high-precision wind field uniformity control. On one hand, a stable airflow channel is formed through the symmetrical design of the air inlet and outlet, generating a uniform wind field and physically ensuring the baseline uniformity of the wind field. A bidirectional ultrasonic anemometer is used to measure the inlet / outlet wind speed in real time, calculate the equivalent wind speed, and utilize the principle of symmetry to eliminate local turbulence errors, improving the reliability of the overall wind speed characterization. On the other hand, a PD / PID controller based on the deviation between the equivalent wind speed and the target value is designed to dynamically adjust the output frequency of the fan inverter, achieving coupled airflow-wind speed control. Simultaneously, the pressure difference across the filter element can monitor different blockage states, triggering alarms in advance to prevent wind field instability caused by sudden changes in filter element resistance.

[0026] According to another embodiment of the present invention, the wind speed uniformity adjustment and control system is further optimized by arranging a micro differential pressure sensor array at equal intervals (10mm interval) along the wind field axis, calculating the differential pressure gradient in real time, and correcting the fan control parameters through gradient feedback to suppress local turbulence caused by thermal disturbance or powder splashing inside the wind field.

[0027] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below may be considered part of the utility model subject matter of this disclosure, provided that such concepts do not contradict each other. Furthermore, all combinations of the claimed subject matter are considered part of the utility model subject matter of this disclosure.

[0028] The foregoing and other aspects, embodiments, and features of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0029] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of the air duct structure of the SLM metal additive manufacturing equipment according to an embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the wind speed adaptive dynamic adjustment system of the SLM metal additive manufacturing equipment according to an embodiment of the present invention. Detailed Implementation

[0032] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0033] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, which illustrate numerous illustrative embodiments. The embodiments disclosed herein are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed herein are not limited to any particular implementation. Furthermore, some aspects of the present invention can be used alone or in any suitable combination with other aspects disclosed herein.

[0034] {Example 1}

[0035] Combination Figure 1 , Figure 2 As shown, the wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to an embodiment of the present invention includes a printing chamber 100, a fan 200, a sensor for monitoring the air intake status and the pressure / wind field status inside the printing chamber, a control system 1000, and an alarm system 1100.

[0036] A printing chamber 100 is provided, which defines a process cavity for additive manufacturing. The printing chamber 100 has an air inlet for receiving gas and an air outlet opposite to the air inlet, thereby creating a uniform air field between the air inlet and the air outlet.

[0037] The fan 200 has its output port connected to the printing chamber 100 via the air intake pipe 300.

[0038] A first anemometer V is installed at the air outlet and air inlet of the printing chamber 100, respectively. in With the second anemometer V out Measure the transverse wind speed V at the air inlet. 进 And the horizontal air velocity V at the outlet 出 And according to the inlet cross wind speed V 进 And the horizontal air velocity V at the outlet 出 Determine the equivalent wind speed V of the uniform wind field between the air outlet and the air inlet, V = (V 进 +V 出 ) / 2.

[0039] A front pressure sensor P is installed on both sides of the filter element in the air inlet duct between the blower and the air outlet of the printing chamber. 前 With the rear pressure sensor P 后 Detect the pressure difference ΔP of the air intake filter element. filter.

[0040] Control system 1000, fan 200, first anemometer V in Second anemometer V out Front pressure sensor P 前 and the rear pressure sensor P 后 Electrical connection, and based on the equivalent wind speed V and the preset ideal wind speed V target The difference is fed into feedback control to control the operation of the frequency converter of the fan 200, so as to follow and compensate for the wind field interference caused by wind speed fluctuations.

[0041] Alarm system 1100 is electrically connected to control system 1000. Control system 1000 is based on the detected pressure difference ΔP of the air inlet filter. filter Exceeding the preset threshold P th An alarm notification was issued.

[0042] As an optional embodiment, the first anemometer V in With the second anemometer V out All use bidirectional ultrasonic anemometers with an accuracy of ±0.05 m / s. The first anemometer, V, is particularly preferred. in With the second anemometer V out They are respectively set 10-50mm downstream of the air outlet (to avoid boundary layer disturbance) and 10-50mm upstream of the air inlet (to monitor the outlet flow field).

[0043] Based on the arrangement of these pressure and wind speed sensors, a symmetrical layout is used to capture global wind field characteristics and avoid local interference.

[0044] As an optional embodiment, the control system 1000 employs a PI closed-loop feedback controller or a PID closed-loop feedback controller, based on the equivalent wind speed V and the preset ideal wind speed V000. target The difference is fed into feedback control.

[0045] As an optional embodiment, the alarm system 1100 includes an audible and visual alarm and uses different alarm prompts to indicate the degree of filter clogging.

[0046] As an optional embodiment, inside the printed chamber 100, multiple equally spaced micro-differential pressure sensors P1, P2, and P3 are arranged along the central axis of the uniform wind field to monitor the wind field pressure and determine the real-time wind field pressure gradient ΔP accordingly. / Δx;

[0047] Micro differential pressure sensors P1, P2, and P3 are all electrically connected to the control system 1000.

[0048] Among them, multiple micro differential pressure sensors P1, P2, and P3 are arranged at equal intervals of 10mm.

[0049] As an optional embodiment, the control system 1000 is configured to receive sampled values ​​from multiple micro differential pressure sensors P1, P2, and P3 at the same time, and determine the wind field pressure gradient ΔP based on the sampled values ​​from the micro differential pressure sensors downstream and upstream of the wind field. / Δx:

[0050] ΔP / Δx=(px3-px1) / d

[0051] Where px3 and px1 represent the sampled values ​​of the differential pressure sensors downstream and upstream of the wind field, respectively, and d represents the distance between the differential pressure sensors downstream and upstream of the wind field.

[0052] Furthermore, the control system 1000 is configured to adjust according to the wind field pressure gradient ΔP. / Δx controls the operation of the frequency converter of the fan.

[0053] As an optional embodiment, the first anemometer V in Second anemometer V out Front pressure sensor P 前 Post-pressure sensor P 后 Multiple differential pressure sensors, P1, P2, and P3, have undergone zero-calibration to eliminate inherent sensor biases, ensure accurate initial data, and avoid systematic errors caused by zero-point drift.

[0054] Among them, the control system 1000 can be an embedded control system, including but not limited to a PLC control system.

[0055] The wind speed uniformity adjustment and control system of the SLM metal additive manufacturing equipment in the above embodiments has the following significant advantages:

[0056] 1) By integrating high-precision measurements from a bidirectional ultrasonic anemometer (±0.05m / s) and a micro differential pressure sensor (10mm resolution), the limitations of traditional single-point anemometers are overcome, enabling high-resolution mapping of three-dimensional wind field conditions. Based on this, PI / PID + differential pressure gradient joint control is combined to achieve a dual closed-loop control architecture (wind speed main loop + differential pressure gradient auxiliary loop), enhancing robustness against complex dynamic disturbances.

[0057] 2) At the same time, based on the dynamic real-time differential pressure of the filter element, threshold alarms and audible and visual graded prompts are implemented to achieve early warning of filter element blockage, realize predictive maintenance (such as filter element life prediction), reduce the risk of sudden downtime, improve equipment efficiency, and provide technical support for the zoned wind field collaborative control of large SLM equipment (such as multi-laser systems).

[0058] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment, characterized in that, include: A printed chamber (100) is provided, which defines the process cavity for additive manufacturing. The printed chamber (100) has an air inlet for receiving gas and an air outlet opposite to the air inlet, creating a uniform air field between the air inlet and the air outlet. A fan (200) has its output port connected to the printing chamber (100) via an air intake pipe (300); A first anemometer (V) is installed at the air outlet and air inlet of the printing chamber (100). in ) and the second anemometer (V out ), Measure the transverse wind speed V at the air inlet. 进 And the horizontal air velocity V at the outlet 出 And according to the inlet cross wind speed V 进 And the horizontal air velocity V at the outlet 出 Determine the equivalent wind speed V of the uniform wind field between the air outlet and the air inlet, V = (V 进 +V 出 ) / 2; A front pressure sensor (P) is installed on both sides of the filter element in the air inlet duct between the blower and the air outlet of the printing chamber. 前 ) and the rear pressure sensor (P 后 ), Detect the pressure difference ΔP of the air intake filter element filter ; The control system (1000), together with the fan (200) and the first anemometer (V) in ), second anemometer (V) out ), front pressure sensor (P) 前 ) and the rear pressure sensor (P 后 Electrical connection, and based on the equivalent wind speed V and the preset ideal wind speed V target The difference is fed into feedback control to control the operation of the frequency converter of the fan (200) to follow and compensate for the wind field interference caused by wind speed fluctuations. An alarm system (1100) is electrically connected to the control system (1000), which is based on the detected pressure difference ΔP of the air intake filter. filter Exceeding the preset threshold P th An alarm notification was issued.

2. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 1, characterized in that, The first anemometer (V in ) and the second anemometer (V out All of them use bidirectional ultrasonic anemometers with an accuracy of ±0.05m / s.

3. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 1, characterized in that, The control system (1000) adopts a PI closed-loop feedback controller or a PID closed-loop feedback controller, based on the equivalent wind speed V and the preset ideal wind speed V. target The difference is fed into feedback control.

4. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 1, characterized in that, The alarm system (1100) includes an audible and visual alarm, and uses different alarm prompts to indicate the degree of filter blockage.

5. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 1, characterized in that, The first anemometer (V in ), second anemometer (V) out ), front pressure sensor (P) 前 ) and the rear pressure sensor (P 后 All have undergone zeroing processing.

6. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 1, characterized in that, Inside the printed chamber (100), multiple equally spaced micro differential pressure sensors (P1, P2, P3) are arranged along the central axis of the uniform wind field to monitor the wind field pressure and determine the real-time wind field pressure gradient ΔP accordingly. / Δx; The micro differential pressure sensors (P1, P2, P3) are all electrically connected to the control system (1000).

7. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 6, characterized in that, The multiple micro differential pressure sensors (P1, P2, P3) are arranged at equal intervals of 10 mm.

8. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 6, characterized in that, The control system (1000) is configured to receive sampled values ​​from multiple micro differential pressure sensors (P1, P2, P3) at the same time, and determine the wind field pressure gradient ΔP based on the sampled values ​​from the micro differential pressure sensors downstream and upstream of the wind field. / Δx: ΔP / Δx=(px3-px1) / d Where px3 and px1 represent the sampled values ​​of the differential pressure sensors downstream and upstream of the wind field, respectively, and d represents the distance between the differential pressure sensors downstream and upstream of the wind field.

9. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to claim 6, characterized in that, The control system (1000) is configured to adjust according to the wind field pressure gradient ΔP. / Δx controls the operation of the frequency converter of the wind turbine.

10. The wind speed uniformity adjustment and control system for SLM metal additive manufacturing equipment according to any one of claims 1-9, characterized in that, The control system (1000) is an embedded control system.

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