Intelligent powder feeder and control method thereof

Abstract

The disclosure provides an intelligent powder feeder and a control method thereof, and relates to the technical field of intelligent manufacturing. The intelligent powder feeder comprises a powder storage container, an electrically controlled gate, a powder feeding pipeline, a powder flow sensor based on a matrix optical fiber, and a controller. The electrically controlled gate is located at a powder outlet of the powder storage container. A first open end of the powder feeding pipeline corresponds to the powder outlet of the powder storage container through the electrically controlled gate. A second opening of the powder feeding pipeline is arranged at a preset position. The powder feeding pipeline comprises a light-transmitting pipe section. A light emitting end and a light receiving end of the powder flow sensor are oppositely arranged at two sides of the light-transmitting pipe section. A signal output end of the powder flow sensor is signal-connected with the controller. The controller is signal-connected with an electrically controlled part of the electrically controlled gate. The controller is used for controlling the opening degree of the electrically controlled gate based on the output signal of the powder flow sensor.

Description

Technical Field

[0001] This specification relates to the field of intelligent manufacturing technology, and in particular to an intelligent powder feeder and its control method. Background Technology

[0002] Powder feeders are widely used in laser cladding, laser additive manufacturing, 3D printing, and spray coating technologies. The continuity and uniformity of the powder feeding process directly affect the stability of the powder processing. Therefore, some embodiments of this specification provide an intelligent powder feeder and control method to ensure a continuously uniform powder output. Summary of the Invention

[0003] This specification provides one or more embodiments of an intelligent powder feeder, including a powder storage container, an electrically controlled gate, a powder feeding pipe, a powder flow sensor based on a matrix optical fiber, and a controller; the electrically controlled gate is located at the powder outlet of the powder storage container; the first opening end of the powder feeding pipe corresponds to the powder outlet of the powder storage container through the electrically controlled gate, and the second opening of the powder feeding pipe is set at a preset position; the powder feeding pipe includes a light-transmitting pipe section; the light emitting end and the light receiving end of the powder flow sensor are arranged opposite to each other on both sides of the light-transmitting pipe section, and the signal output end of the powder flow sensor is signal-connected to the controller; the controller is signal-connected to the electrical control part of the electrically controlled gate, and the controller is used to control the opening degree of the electrically controlled gate based on the output signal of the powder flow sensor; wherein, the light emitting end and the light receiving end of the powder flow sensor are respectively provided with two or more rows of optical fiber ports, and the two or more rows of optical fiber ports are arranged along the length direction of the light-transmitting pipe section, or the arrangement direction of the two or more rows of optical fiber ports of the light emitting end and the light receiving end has an inclination angle relative to the length direction of the light-transmitting pipe section.

[0004] The intelligent powder feeder according to some embodiments of this specification further includes a vibrator; the vibrator has a transmission connection with the powder storage container, and the vibrator has a signal connection with the controller so as to operate under the control of the controller;

[0005] The powder storage container is an eccentric funnel.

[0006] According to some embodiments of the intelligent powder feeder described in this specification, the light-transmitting tube segment is adjacent to the first open end or the distance between the light-transmitting tube segment and the first open end does not exceed 1 cm.

[0007] According to some embodiments of the intelligent powder feeder described in this specification, the cross-section of the light-transmitting tube section is arc-shaped at the location corresponding to the light emitting end and light receiving end of the powder flow sensor.

[0008] According to some embodiments of the intelligent powder feeder described in this specification, a light-diffusing element is provided between the light-transmitting tube section and the light-emitting end, and a light-concentrating element is provided between the light-transmitting tube section and the light-receiving end.

[0009] According to some embodiments of the intelligent powder feeder described in this specification, the number of light emitting ends and light receiving ends are both 2. The first light emitting end and the first light receiving end are arranged opposite each other on both sides of the light-transmitting tube segment along a first center line of the cross-section of the light-transmitting tube segment, and the second light emitting end and the second light receiving end are arranged opposite each other on both sides of the light-transmitting tube segment along a second center line of the cross-section of the light-transmitting tube segment; the first center line and the second center line are orthogonal.

[0010] This specification provides one or more embodiments of a control method for the aforementioned intelligent powder feeder, executed by the controller, comprising: acquiring the output signal of the powder flow sensor; comparing the output signal with a first threshold; when the comparison result reflects that the actual powder quantity is greater than the set powder quantity, controlling the opening of the electrically controlled gate to decrease; and when the comparison result reflects that the actual powder quantity is less than the set powder quantity, controlling the opening of the electrically controlled gate to increase.

[0011] The control method described in some embodiments of this specification further includes: controlling the opening degree of the electrically controlled gate so that the amount of powder in the powder feeding pipeline reaches the set amount of powder measured by the calibration device; acquiring the output signals of the powder flow sensor at two or more time points during the period when the amount of powder in the powder feeding pipeline reaches the set amount of powder measured by the calibration device; and determining the first threshold based on the output signals at the two or more time points.

[0012] The control method described in some embodiments of this specification further includes: when the comparison result still reflects that the actual powder amount is less than the set powder amount after increasing the opening degree of the electrically controlled gate, controlling the vibrator to start working; when the vibrator is working and the comparison result still reflects that the actual powder amount is less than the set powder amount, issuing a prompt so that the operator can check whether the powder storage container is short of powder or whether the powder outlet is blocked.

[0013] According to the control method described in some embodiments of this specification, the output signal of the powder flow sensor reflects the average value of the optical signal intensity received by each row of optical fiber ports on the optical receiver. Attached Figure Description

[0014] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. The same numbers in the drawings denote the same structures or steps.

[0015] Figure 1This is a structural schematic diagram of an intelligent powder feeder according to some embodiments of this specification.

[0016] Figure 2 This is a structural schematic diagram of an electrically controlled gate according to some embodiments of this specification.

[0017] Figure 3 This is a schematic diagram showing the relative positions of the light emitting end (or light receiving end) and the light-transmitting tube section of a powder flow sensor according to some embodiments of this specification.

[0018] Figure 4 This is a schematic diagram showing the relative positions of the light emitting end and the light receiving end of the powder flow sensor with respect to the light-transmitting tube section, according to other embodiments of this specification.

[0019] Figure 5 This is a schematic diagram showing the relative positions of the light emitting end and the light receiving end of the powder flow sensor with respect to the light-transmitting tube section, according to some embodiments of this specification.

[0020] Figure 6 This is a schematic diagram showing the relative positions of the light emitting end and the light receiving end of the powder flow sensor with respect to the light-transmitting tube section, according to some embodiments of this specification.

[0021] Figure 7 This is a flowchart of a control method according to some embodiments of this specification. Detailed Implementation

[0022] To more clearly illustrate the technical solutions of the embodiments in this specification, the embodiments will be described in detail below with reference to the accompanying drawings. Obviously, the content described below are some examples or embodiments of this specification. For those skilled in the art, without creative effort, the technical solutions or means disclosed in this specification can be applied to other scenarios based on this technical content.

[0023] It should be understood that the terms "system," "device," "unit," and / or "module" used in this specification are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0024] Unless otherwise specified, the technical terms used to describe components, elements, etc. in this specification are not singular but may include plural. Generally speaking, terms such as "comprising" or "including" only indicate that explicitly identified steps, elements, or components are included, and these steps, elements, and components do not constitute an exclusive list, as the described method or apparatus may also include other steps or components.

[0025] This specification uses flowcharts to illustrate the operational steps performed by the apparatus or system of related embodiments. However, unless otherwise specified, the order in which these steps are described should not be construed as a limitation on the order of execution. Those skilled in the art can adjust the order of these steps based on the knowledge and information conveyed by the embodiments in this specification. Such adjustments include, but are not limited to, reversing the order of steps, merging multiple steps, and splitting a step.

[0026] Powder feeders are widely used in laser cladding, laser additive manufacturing, 3D printing, and spraying technologies. Taking laser cladding as an example, this technology involves adding cladding material to the surface of a substrate and using a high-energy-density laser beam to melt and solidify it together with a thin layer on the substrate surface, thereby forming a metallurgically bonded cladding layer. The powder feeder is a crucial piece of equipment in laser cladding. Its function is to transport powdered cladding material (such as metal powder) through a powder feeding pipe to a mixing zone, and then use a carrier gas to carry the powder away, for example, to a processing zone. In the processing zone, a high-energy laser beam is focused onto the surface of the metal substrate to form a molten pool. The carrier gas then feeds the powder into the molten pool through a nozzle, causing it to melt and solidify together with the molten pool on the substrate surface, forming the cladding layer. During this process, the ability of the powder feeder to continuously, stably, and uniformly deliver the cladding powder directly affects the quality of the cladding layer on the substrate surface.

[0027] Therefore, some embodiments of this specification propose an intelligent powder feeder that uses a powder flow sensor to sense the amount of powder in the powder feeding pipe, so as to accurately sense the powder feeding amount and control the powder feeder to continuously and stably deliver powder.

[0028] Figure 1 This is a structural schematic diagram of an intelligent powder feeder according to some embodiments of this specification. In some embodiments, the main body of the intelligent powder feeder includes a powder storage container 1, an electrically controlled gate 4, a powder feeding pipe 9, and a controller 10.

[0029] The powder storage container 1 is used to hold powder. It has a powder inlet and a powder outlet. The powder inlet facilitates the addition of large quantities of powder, while the powder outlet allows the powder to drain out and be transported to a designated area for further processing. Generally, the diameter of the powder inlet is significantly larger than the diameter of the powder outlet. In some embodiments, the powder storage container can be funnel-shaped, specifically an eccentric funnel. For a funnel-shaped powder storage container, it is considered an eccentric funnel when the center point of the powder outlet is not collinear with the center point of the powder inlet. Further, the powder storage container can be... Figure 1 The asymmetrical eccentric funnel or asymmetrical single-sided funnel shown is designed to reduce frictional resistance between powders, allowing the metal powder to fall smoothly.

[0030] The powder feeding pipe 9 is used to transport powder leaking from the powder storage container 1 to a preset position. Taking laser cladding as an example, the preset position can be the mixing zone 7. The first opening of the powder feeding pipe 9 (e.g., Figure 1 The upper opening shown corresponds to the powder outlet of the powder storage container 1, and the second opening (as shown) is configured accordingly. Figure 1 The lower opening (as shown) is positioned at the preset location. An electrically controlled gate 4 is also provided between the first opening and the powder outlet of the powder storage container 1. When the electrically controlled gate 4 is opened, powder falls from the powder storage container 1 through the powder outlet into the powder delivery pipe. By controlling the opening degree of the electrically controlled gate 4, the powder delivery amount, or the powder flow rate in the powder delivery pipe, can be controlled. The opening degree is positively correlated with the opening area of ​​the gate.

[0031] The controller 10 can be a programmable controller, such as a microcontroller, CPLD (Complex Programmable Logic Device), PLC (Programmable Logic Controller), DCS (Distributed Control System), etc. The controller 10 has a signal connection with the electrical control unit 5 of the electrically controlled gate 4, and the controller 10 can control the opening degree of the electrically controlled gate 4. In some embodiments, the electrically controlled gate may include an electrical control unit and an actuator. The electrical control unit receives control signals and drives the actuator to move, realizing the opening and closing of the gate. In some embodiments, the electrical control unit 5 may include a motor, which operates under the control signals of the controller. As an example, the motor may further be a stepper motor, servo motor, switched reluctance motor, asynchronous motor, etc. In some embodiments, the actuator of the electrically controlled gate performs linear motion, therefore a transmission element 6 is needed to convert the rotation of the motor into linear motion of the actuator. As an example, the transmission element may be a ball screw, which has low frictional resistance, helping to accurately control the movement of the actuator, and thus accurately control the powder output. In some embodiments, a cover plate 2 may be provided above the electrically controlled gate 4 to enclose and protect the portion below the electrically controlled gate.

[0032] Figure 2The specification illustrates the actuator structure of an electrically controlled gate according to some embodiments. The actuator includes a movable part 41 and a fixed part 42. The movable part 41 is connected to a motor shaft via a transmission element 6. The movable part 41 is stacked on top of the fixed part 42 and is movable relative to the fixed part 42. As an example, the movable part 41 and the fixed part 42 can be coupled via a slide rail. The opposing edges of the movable part 41 and the fixed part 42 are respectively provided with parabolic notches. The movement of the movable part 41 relative to the fixed part 42 changes the overlapping area of ​​the notches, thus changing the opening degree of the electrically controlled gate. In some embodiments, the movable part 41 can be stacked below the fixed part 42, achieving the same technical effect. In yet another embodiment, the movable part 41 and the fixed part 42 can be arranged coplanarly opposite each other. In this case, no notches are needed on their edges. When their opposing edges abut together, the gate can be closed. Furthermore, the fixed part 42 can be omitted, and the movable part 41, in conjunction with the powder outlet, can achieve the opening and closing of the gate. In contrast, the movable part 41 and the fixed part 42 are stacked one on top of the other, and their opposing edges are respectively provided with notches with parabolic contours, which can make the opening of the electric gate more continuous and uniform, and help to achieve precise control of the powder output.

[0033] See also Figure 2 When the controller 10 instructs the electric gate 4 to increase its opening, the movable part 41 moves away from the fixed part 42, the gap overlap area increases, and more powder falls from the powder outlet into the powder delivery pipe 9. When the controller 10 instructs the electric gate 4 to decrease its opening, the movable part 41 moves closer to the fixed part 42, the gap overlap area decreases, and less powder falls from the powder outlet into the powder delivery pipe 9.

[0034] To ensure a consistently stable powder delivery rate, some embodiments of this specification provide a powder flow detection device based on a matrix optical fiber powder flow sensor. The powder flow sensor includes a light emitting end and a light receiving end. The light emitting end emits light, such as infrared light with a wavelength range of 0.76 micrometers to 1000 micrometers, or ultraviolet light with a wavelength range below 400 nanometers. The light receiving end is positioned opposite the light emitting end to receive the light emitted from the other end. The object to be detected is placed between the two ends. The light receiving end determines the presence of the object to be detected or the quantity of the object to be detected (such as powder particles) by sensing the intensity of the received light. The signal output end of the powder flow sensor is connected to the controller, which controls the opening degree of the electrically controlled gate based on the output signal of the powder flow sensor.

[0035] In some embodiments, the powder feeding pipe 9 includes a light-transmitting pipe segment. For example, the material of the light-transmitting pipe segment may include one or more combinations of the following: glass, optical plastic, transparent fiberglass, light-transmitting concrete, light-transmitting film, etc., wherein the glass may further include: quartz glass, ultraviolet-transmitting black glass, soda-lime silicon glass that transmits short-wave ultraviolet light, and soda-lime ultraviolet glass, etc. In some embodiments, the light-transmitting pipe segment 91 may be located at any position on the powder feeding pipe 9, or the light-transmitting pipe segment 91 may be adjacent to the first opening. Adjacency can be understood as the light-transmitting pipe segment 91 and the first opening being adjacent to each other without any other pipe segments in between, or the adjacency can be understood as the first opening being an opening of the light-transmitting pipe segment 91. In still other embodiments, the light-transmitting pipe segment 91 may be located near the first opening, such as when other pipe segments of the powder feeding pipe are spaced between the light-transmitting pipe segment and the first opening end, but the distance between the light-transmitting pipe segment and the first opening end does not exceed a preset value. For example, the preset value may be 0.1cm, 0.5cm, 1cm, 2cm, 3cm, 5cm, etc. The light-transmitting pipe section 91 is located near the first opening of the powder feeding pipe 9, which can effectively shorten the detection loop of powder flow. Within a microsecond time interval after the powder is discharged from the powder storage container, the controller can receive the output signal of the powder flow sensor and make corresponding adjustments to the opening of the electric control gate.

[0036] like Figure 2 As shown, the light emitting end 81 and the light receiving end 82 of the powder flow sensor are positioned opposite each other on both sides of the light-transmitting tube section 91. At the light emitting end 81, the light emitted by the light source propagates through the optical fiber 812 and the optical fiber port 811 and diverges into the external space, such as the light-transmitting tube section 91. The light then enters the optical fiber port 821 in the light receiving end 82 through the light-transmitting tube section 91, and is further transmitted by the optical fiber 822 to the optical fiber amplifier (e.g., ...). Figure 1 The fiber optic amplifier 83 shown converts the optical signal into an electrical signal with voltage and / or current within a certain range, and outputs it to the controller.

[0037] In practical applications, the size of powder particles is generally at the micrometer level. For example, the diameter of metal powder particles used in laser cladding is between 20 and 50 micrometers. The powder falls dynamically and randomly from the outlet of the powder storage container to the powder delivery pipe. Real-time detection of this dynamic distribution is a key factor affecting detection accuracy. In other words, if only a single row of fiber optic ports is used, it is very easy to miss powder particles. Therefore, in some embodiments of this specification, the optical transmitter of the powder flow sensor is provided with two or more rows of fiber optic ports 811. These two or more rows of fiber optic ports are arranged along the length of the light-transmitting pipe section. In this way, the lower row of fiber optic ports can supplement the detection of powder particles missed by the upper row of fiber optic ports. As an example, the optical transmitter is provided with 8 rows and 2 columns of fiber optic ports, arranged sequentially along the length of the light-transmitting pipe section 91. Correspondingly (or approximately mirror-symmetrically), the optical receiver 82 is also provided with multiple fiber optic ports of the same number and position. Figure 2 (Not shown in the image). In some embodiments, the fiber optic ports can also be configured with 2 rows, 4 rows, 7 rows, 10 rows, etc.

[0038] In some embodiments, the diameter or width of the light-transmitting tube segment is large, while the data of the fiber optic ports at the light-emitting or light-receiving end, specifically the fiber optic ports in each row, may be small and unable to cover the diameter or width range of the light-transmitting tube segment. This can also lead to inaccurate detection. In some embodiments, the light-emitting end and the light-receiving end can be tilted at a certain angle relative to the same side of the light-transmitting tube segment, thereby making the arrangement direction of the two or more rows of fiber optic ports tilted at an angle relative to the length direction of the light-transmitting tube segment. Figure 3 This is a schematic diagram illustrating the relative positions of the optical transmitter and receiver of a powder flow sensor with respect to the light-transmitting tube section, according to some embodiments of this specification. For clarity, the diagram only shows the arrangement direction of the two or more rows of optical fiber ports of the optical transmitter 81 (or optical receiver 82) at an angle relative to the length direction of the light-transmitting tube section 91. α The optical fiber ports of the optical transmitter 81 (or optical receiver 82) are arranged in the same way, or symmetrically with respect to the translucent tube section, to ensure that the optical receiver can fully receive the remaining light after the emitted light from the optical transmitter passes through the translucent tube section. In some embodiments, the tilt angle... α An acute angle, for example, can be 2°, 5°, 10°, 12°, 15°, etc.

[0039] To increase the detection range of the powder flow sensor, in some embodiments, the cross-section of the light-transmitting tube section is arc-shaped at the points corresponding to the light emitting and receiving ends of the powder flow sensor. Figure 4This is a schematic diagram showing the relative positions of the light emitting end and light receiving end of the powder flow sensor with respect to the light-transmitting tube section, according to other embodiments of this specification. The figure shows a top-view schematic diagram of the relative positions of the light-transmitting tube section 91, the light emitting end 81, and the light receiving end 82, respectively. The portions of the cross-section of the light-transmitting tube section 91 corresponding to the light emitting end 81 and the light receiving end 82 are arc-shaped, for example, they can be circular arcs. From... Figure 4 Viewed from left to right, light is emitted from the light emitting end 81 and strikes the arc surface of the corresponding light-transmitting tube segment 91. The arc surface diverges the incident light, thereby expanding the coverage area of ​​the emitted light so that it completely covers the cross-section of the light-transmitting tube segment. Light passing through the interior of the light-transmitting tube segment reaches the arc surface opposite the light receiving end 82. This arc surface converges the incident light, causing more of the remaining light after passing through the light-transmitting tube segment to converge at the fiber optic port of the light receiving end 82 and enter the light receiving end 82. In some embodiments, the light-transmitting tube segment can be a segment with a circular or elliptical cross-section. When the cross-section of the light-transmitting tube segment is elliptical, the light emitting end and the light receiving end are positioned opposite each other along the long axis of the cross-section of the light-transmitting tube segment. This ensures that the portion of the cross-section with a larger curvature is opposite the light emitting end (light receiving end), achieving better light divergence and convergence effects, thus significantly expanding the detection range even with a smaller number of fiber optic port rows. This embodiment utilizes the geometric and optical characteristics of the light-transmitting tube section itself to expand the detection range of the fiber optic matrix sensor, improve detection accuracy, and simultaneously simplify and miniaturize the detection device structure.

[0040] Figure 5 This is a schematic diagram illustrating the relative positions of the light emitting end and light receiving end of a powder flow sensor with respect to the light-transmitting tube section, according to some embodiments of this specification. The diagram shows the relative positions of the light-transmitting tube section, light emitting end, and light receiving end from a top-view perspective. As shown, a diffusing element 13 is disposed between the light-transmitting tube section 91 and the light emitting end 81, and a focusing element 14 is disposed between the light-transmitting tube section 91 and the light receiving end 82. The dotted lines in the diagram represent light rays. For example, the diffusing element 13 can be a concave lens, and the focusing element 14 can be a convex lens. Figure 5Viewed from left to right, light is emitted from the light emitting end 81 and strikes the diffusing element 13. The diffusing element 13 diverges the incident light, thereby expanding the coverage area of ​​the emitted light so that it completely covers the cross-section of the light-transmitting tube. The light passing through the inside of the light-transmitting tube reaches the focusing element 14, which converges the incident light, thus converging more of the remaining light after passing through the light-transmitting tube to the fiber optic port of the light receiving end 82 and entering the light receiving end 82. This embodiment adds specialized optical elements to realize the divergence and convergence of light, expanding the detection range of the sensor. At the same time, it is not dependent on the shape of the light-transmitting tube. In this case, the light-transmitting tube can be flexibly set as a tube with a rectangular, pentagonal, hexagonal, triangular, circular, or elliptical cross-section as needed.

[0041] Figure 6 This is a schematic diagram illustrating the relative positions of the light emitting end and light receiving end of the powder flow sensor with respect to the light-transmitting tube section, according to some embodiments of this specification. The figure shows a top view of the relative positions of the light-transmitting tube section, the light emitting end, and the light receiving end. As shown in the figure, there are two light emitting ends and two light receiving ends. The first light emitting end 81 and the first light receiving end 82 (or simply the first set of transceivers) are positioned opposite each other on both sides of the light-transmitting tube section 91 along a first centerline (a horizontally extending dotted line in the figure). The second light emitting end 84 and the second light receiving end 85 (or simply the second set of transceivers) are positioned opposite each other on both sides of the light-transmitting tube section 91 along a second centerline (a vertically extending dotted line in the figure). The centerline is a straight line passing through the center point of the cross-section. In some embodiments, the first centerline and the second centerline are coplanar and orthogonal. This embodiment expands the sensor's detection range by setting up two sets of light emitting and receiving ends to detect powder from different angles of the light-transmitting tube segment. Furthermore, it is not dependent on the shape of the light-transmitting tube segment; the segment can be flexibly configured with a rectangular, pentagonal, hexagonal, triangular, circular, or elliptical cross-section as needed. In some embodiments, the first and second center lines may not be coplanar. In this case, the first and second sets of transceiver ends can have different heights relative to the light-transmitting tube segment, increasing the detection range while effectively preventing powder from being missed.

[0042] Some embodiments of this specification also provide a control method for the aforementioned intelligent powder feeder, which can be executed by the controller in the intelligent powder feeder. Figure 7 This is a flowchart of a control method according to some embodiments of this specification, such as... Figure 7 As shown, process 700 includes the following steps.

[0043] Step 710: Obtain the output signal of the powder flow sensor.

[0044] In some embodiments, the output signal of the powder flow sensor is an electrical signal reflecting the powder flow rate or concentration in the light-transmitting tube. Inside the powder flow sensor, an optical fiber amplifier converts the optical signal output from the optical fiber at the optical receiver into an electrical signal within a certain voltage range (e.g., 0~3V, 0~5V, 0~10V, etc.). In some embodiments, the greater the attenuation of the optical signal received by the optical receiver (i.e., the more light is absorbed by the powder in the light-transmitting tube), the higher the voltage value of the output signal; conversely, the greater the attenuation of the optical signal received by the optical receiver (i.e., the more light is absorbed by the powder in the light-transmitting tube), the lower the voltage value of the output signal. That is, the optical signal intensity and the voltage value can be positively or negatively correlated, which can be determined by the amplification or adaptation circuit inside the powder flow sensor. As an example, the voltage value of the output signal of the powder flow sensor can be proportional to the optical attenuation. For example, when the attenuation is 20%, the voltage value of the output signal of the powder flow sensor is 1V, and when the attenuation is 100%, the voltage value of the output signal of the powder flow sensor is 5V.

[0045] When the optical fiber ports of the optical receiver are arranged in multiple rows, the output signal can reflect the sum or average of the optical signal intensities from each row of optical fiber ports. Specifically, the optical signals received from each row of optical fiber ports can be aggregated and input into an optical fiber amplifier to obtain the output signal. Alternatively, the optical signals received from each row of optical fiber ports can be converted into electrical signals, and the average of the electrical signals can be calculated to obtain the output signal. Averaging the optical signals acquired from each row of optical fiber ports can reduce the false negative rate of powder particles and avoid detection errors caused by repeated detection of the same powder particle, thereby improving the detection accuracy of the powder flow sensor.

[0046] When there are multiple transceiver sets, the output signal can reflect the cumulative or average value of the optical signal intensities received by the optical receivers in each transceiver set. Specifically, the optical signals received by the optical fiber ports of each optical receiver can be aggregated and input into an optical fiber amplifier to obtain the output signal. Alternatively, the optical signals received by each optical receiver can be converted into electrical signals, and the average value of the electrical signals can be calculated to obtain the output signal. Averaging the optical signals acquired by each optical receiver can increase the detection coverage of the powder flow sensor, while avoiding detection errors caused by repeated detection of the same powder particles, thereby improving the detection accuracy of the powder flow sensor.

[0047] Step 720: Compare the output signal with the first threshold.

[0048] The first threshold can be an electrical signal parameter, such as a voltage value, corresponding to a set powder quantity. The powder quantity can specifically be powder flow rate or powder concentration. In some embodiments, the first threshold can be determined by a calibration device, which can be a device for measuring powder quantity, such as a high-precision electronic scale.

[0049] The controller controls the electrically controlled gate to open to a certain degree, collecting powder falling from the second opening of the powder delivery pipe within a certain time period, such as 10 seconds, 30 seconds, 1 minute, 3 minutes, etc. A calibration device measures the amount of collected powder, such as powder mass. Based on the measured powder amount and the specified time, the amount of powder in the powder delivery pipe per unit time, i.e., the powder flow rate, can be obtained. Based on this, combined with the pipe volume, the powder concentration can be further obtained. The opening degree of the electrically controlled gate is adjusted so that the powder amount in the powder delivery pipe reaches the set powder amount measured by the calibration device. When the set powder amount is a set powder concentration or a set powder flow rate, the powder mass corresponding to a certain time period can be calculated based on the time and pipe volume. Then, the actual powder output mass can be measured by the calibration device to see if it corresponds to the set powder amount. When the calibration device indicates that the powder amount in the powder delivery pipe has reached the set powder amount, the output signals of the powder flow sensor at two or more time points are acquired. These two or more time points can be evenly spaced at intervals of 5 seconds, 1 second, 0.5 seconds, 0.01 seconds, or shorter. The first threshold is determined based on the output signals at two or more time points. For example, the average of the output signals at the two or more time points can be used as the first threshold. Therefore, the first threshold can be considered to correspond to a set powder amount.

[0050] Step 730: When the comparison result shows that the actual amount of powder is greater than the set amount of powder, the opening degree of the electrically controlled gate is reduced.

[0051] In some embodiments, when the output signal is greater than a first threshold, the comparison result is considered to reflect that the actual powder quantity is greater than the set powder quantity. In some embodiments, when the output signal is less than the first threshold, the comparison result is considered to reflect that the actual powder quantity is greater than the set powder quantity. This depends specifically on whether the output signal of the powder flow sensor is positively or negatively correlated with the intensity of the light signal received by the light receiver.

[0052] As an example, the controller can control the opening degree of the electrically controlled gate at a frequency of 3-5 times / second, with each change being 1% of the total opening degree. The total opening degree can be the size of the electrically controlled gate at its maximum opening, such as its maximum inner diameter. Figure 2For example, the total opening can be the distance between the apex of the parabolic notch between the moving part 41 and the fixed part 42 when the moving part 41 reaches its farthest separation position. In this way, the controller can adjust the opening and closing degree of the electronically controlled gate in multiple gradients, making the powder output change more uniform and continuous.

[0053] Step 740: When the comparison result shows that the actual amount of powder is less than the set amount of powder, the opening degree of the electrically controlled gate is increased.

[0054] In some embodiments, when the output signal is less than a first threshold, it is considered that the result of the aforementioned comparison reflects that the actual powder quantity is less than the set powder quantity. In some embodiments, when the output signal is greater than the first threshold, it is considered that the result of the aforementioned comparison reflects that the actual powder quantity is less than the set powder quantity. Specifically, it depends on whether the output signal of the powder flow sensor is positively or negatively correlated with the intensity of the light signal received by the light receiver. The frequency and amount of the opening change are described in the relevant section of step 730 and will not be repeated here.

[0055] In some embodiments, the intelligent powder feeder may also include a display screen (such as...) Figure 1 The display screen 11 is connected to the controller via a signal connection. The display screen can show the set powder quantity and the actual powder quantity measured by the powder flow sensor. In some embodiments, an input device, such as a keyboard or mouse, or a touch screen, can be provided. Operators can input control commands to the controller via the input device, such as the open / stop command of the electric gate's control unit, or the set powder quantity.

[0056] In some embodiments, the intelligent powder feeder may also include a vibrator (such as...) Figure 1The vibrator 12 shown has a transmission connection with the powder storage container; for example, the vibrator can be fixed to the side wall of the powder storage container. The vibrator also has a signal connection with the controller, which can control the operation of the vibrator. For example, the controller can control the vibrator to operate at regular intervals. After the vibrator operates, it drives the powder storage container to vibrate, which can evenly distribute the powder in the powder storage container, ensuring continuous and uniform powder output. In some embodiments, the controller can also control the operation of the vibrator by combining the opening degree of the electrically controlled gate and the comparison result between the measured powder quantity and the set powder quantity. Specifically, after increasing the opening degree of the electrically controlled gate, the controller can continuously acquire the output signal of the powder flow sensor and compare it with a first threshold. If the comparison result still reflects that the actual powder quantity is less than the set powder quantity, the controller controls the vibrator to start operating. Further, when the vibrator is operating, if the comparison result still reflects that the actual powder quantity is less than the set powder quantity, the controller can issue a prompt so that the operator can check whether the powder storage container is short of powder or whether the powder outlet is blocked. As an example, the prompt can be an audible alarm or a prompt text output through the display screen.

[0057] In some embodiments, the intelligent powder feeder also incorporates other types of sensors, such as sensors for detecting the gate position and sensors for detecting the amount of powder in the storage container. The controller of the intelligent powder feeder can better control the opening of the electrically controlled gate or issue more accurate alerts based on the output signals of these various sensors. For example, when the output signal of the powder flow sensor indicates that the actual powder quantity is consistently less than the set powder quantity, the controller can further obtain the gate position and / or the powder quantity in the storage container through the aforementioned sensors, thereby issuing more targeted alert signals.

[0058] pass Figure 7 The process 700 shown can control the intelligent powder feeder to automatically adjust the amount of powder in the powder feeding pipeline to stabilize it at the set amount of powder. When the powder storage container is low on powder or the powder outlet is clogged, the intelligent powder feeder can issue an alarm in time, effectively ensuring that the powder feeding process is continuous and uniform.

[0059] The beneficial effects that the embodiments of this specification may bring include, but are not limited to: (1) arranging multiple rows of optical fiber ports of the powder flow sensor along the length of the transparent pipe section can effectively avoid missing the detection of powder particles in the pipe; (2) expanding the detection coverage of the powder flow sensor, making the powder quantity detection more accurate; (3) the control method of the intelligent powder feeder effectively ensures that the powder feeding process is continuous and uniform. It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced can be any one or a combination of the above, or any other possible beneficial effects.

[0060] The basic concepts have been described above. It is obvious that the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to this specification by those skilled in the art. Such modifications, improvements, and corrections are taught in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

Claims

1. An intelligent powder feeder, comprising a powder storage container, an electrically controlled gate, a powder feeding pipe, a powder flow sensor based on a matrix optical fiber, and a controller; The electrically controlled gate is located at the powder outlet of the powder storage container; The first opening of the powder delivery pipe corresponds to the powder outlet of the powder storage container via the electrically controlled gate, and the second opening of the powder delivery pipe is set at a preset position; the powder delivery pipe includes a light-transmitting pipe section. The powder flow sensor includes a light emitting end and a light receiving end, which are disposed opposite to each other on both sides of the light-transmitting tube section. The signal output end of the powder flow sensor is connected to the controller. The controller is connected to the electrical control unit of the electrically controlled gate, and the controller is used to control the opening degree of the electrically controlled gate based on the output signal of the powder flow sensor; in, The optical transmitter and optical receiver of the powder flow sensor are each provided with two or more rows of optical fiber ports, and the optical transmitter and optical receiver of the powder sensor are each provided with two columns of optical fiber ports. The arrangement of the optical fiber ports of the optical transmitter and the optical receiver is symmetrical with respect to the trans-center plane of the light-transmitting pipe section, and the arrangement direction of the two or more rows of optical fiber ports of the optical transmitter and the optical receiver has an inclination angle with respect to the length direction of the light-transmitting pipe section, so that the detection range of the powder flow sensor covers the diameter or width range of the light-transmitting pipe section. The cross-section of the light-transmitting tube segment is elliptical. The light emitting end and the light receiving end are arranged opposite each other on both sides of the light-transmitting tube segment along the long axis of the cross-section of the light-transmitting tube segment, so that the part with a larger curvature on the cross-section of the light-transmitting tube segment is opposite to the light emitting end or the light receiving end. A light-diffusing element is provided between the light-transmitting tube segment and the light-emitting end, and a light-concentrating element is provided between the light-transmitting tube segment and the light-receiving end.

2. The intelligent powder feeder according to claim 1 further includes a vibrator; the vibrator is connected to the powder storage container by a transmission connection, and the vibrator is connected to the controller by a signal connection so as to operate under the control of the controller; The powder storage container is an eccentric funnel.

3. The intelligent powder feeder according to claim 1, wherein the light-transmitting tube segment is adjacent to the first open end or the distance between the light-transmitting tube segment and the first open end does not exceed 1 cm.

4. The intelligent powder feeder according to claim 1, wherein the cross-section of the light-transmitting tube section is arc-shaped at the point corresponding to the light emitting end and light receiving end of the powder flow sensor.

5. The intelligent powder feeder according to claim 1, wherein the number of the light emitting end and the number of the light receiving end are both 2, wherein, A first light emitting end and a first light receiving end are disposed opposite each other on both sides of the light-transmitting tube section along a first center line of the cross-section of the light-transmitting tube section, and a second light emitting end and a second light receiving end are disposed opposite each other on both sides of the light-transmitting tube section along a second center line of the cross-section of the light-transmitting tube section. The first centerline and the second centerline are orthogonal.

6. The control method for the intelligent powder feeder according to claim 2, executed by the controller, includes: Acquire the output signal of the powder flow sensor; The output signal is compared with a first threshold. When the comparison result shows that the actual powder amount is greater than the set powder amount, the opening degree of the electrically controlled gate is reduced; when the comparison result shows that the actual powder amount is less than the set powder amount, the opening degree of the electrically controlled gate is increased.

7. The control method according to claim 6 further includes: The opening degree of the electrically controlled gate is controlled so that the amount of powder in the powder feeding pipeline reaches the set amount of powder measured by the calibration equipment; Acquire the output signals of the powder flow sensor at two or more time points during the period when the powder quantity in the powder delivery pipeline reaches the set powder quantity measured by the calibration equipment; The first threshold is determined based on the output signals at the two or more time points.

8. The control method according to claim 7, further comprising: After increasing the opening of the electrically controlled gate, if the comparison result still reflects that the actual powder amount is less than the set powder amount, the vibrator is controlled to start working. When the vibrator is working, and the comparison result still reflects that the actual amount of powder is less than the set amount of powder, a prompt is issued so that the staff can check whether the powder storage container is short of powder or whether the powder outlet is blocked.

9. The control method according to claim 8, wherein the output signal of the powder flow sensor reflects the average value of the optical signal intensity received by each row of optical fiber ports on the optical receiver.

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