A laser additive powder feeding device

Abstract

The application discloses a laser additive powder feeding device, and relates to the technical field of laser additive manufacturing, which is used for realizing online weighing and real-time adjustment of multiple powder paths and improving additive manufacturing efficiency. The laser additive powder feeding device comprises a bearing frame, a powder supply unit, a powder weighing unit, a powder mixing unit and a control system, and the powder supply unit supplies at least two kinds of powder. The powder weighing unit is communicated with the powder supply unit, is used for receiving the powder, and weighs the weight of the powder respectively. The powder mixing unit is communicated with the powder weighing unit, is used for receiving and mixing the at least two kinds of powder and outputting. The control system is electrically connected with the powder supply unit, is used for controlling the powder supply unit to start or stop supplying the powder. The control system is electrically connected with the powder weighing unit, is used for receiving the weight signal of the powder, and when the weight of any kind of powder reaches a preset value, the control system controls the powder supply unit to stop supplying the powder. The control system is electrically connected with the powder mixing unit, is used for controlling the powder mixing unit to start or stop mixing the powder, and controls the powder mixing unit to output the powder.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser additive technology, in particular to a laser additive powder feeding device. BACKGROUND

[0002] Laser additive technology is a processing method for workpiece surface modification or additive manufacturing using laser as a heat source. When the additive material is multiple powders, there are differences in particle size, density and shape of different types of powders, and how to realize quantitative delivery and uniform mixing of multiple powders faces great challenges.

[0003] In the prior art, the mixing of multiple powders generally adopts an offline stirring and mixing method, which mainly uses manual stirring or machine stirring to mix and stir multiple powders weighed separately in advance, but this method affects the efficiency of additive manufacturing. SUMMARY

[0004] The purpose of the present application is to provide a laser additive powder feeding device for realizing online weighing and real-time adjustment of multiple powders and improving additive efficiency.

[0005] In order to achieve the above purpose, the present application provides a laser additive powder feeding device, which comprises a bearing frame, a powder supply unit, a powder weighing unit, a powder mixing unit and a control system. The powder supply unit is arranged on the bearing frame and is used to supply at least two powders by gravity. The powder weighing unit is arranged on the bearing frame and is in communication with the powder supply unit, used to receive powders and weigh the received at least two powders respectively. The powder mixing unit is in communication with the powder weighing unit, used to receive, mix and output the at least two powders weighed by the powder weighing unit. The control system is electrically connected with the powder supply unit, used to control the start or stop of the powder supply unit. The control system is electrically connected with the powder weighing unit, used to receive the weight signals of the at least two powders weighed by the powder weighing unit, and when the weight of any one of the powders weighed by the powder weighing unit reaches a preset value, the control system controls the powder supply unit to stop supplying the powder. The control system is also electrically connected with the powder mixing unit, used to control the start or stop of the powder mixing unit for mixing the at least two powders, and control the powder mixing unit to output the mixed powders.

[0006] In the technical solution, the laser additive powder feeding device comprises a bearing frame, a powder supply unit, a powder weighing unit, a powder mixing unit and a control system. The powder supply unit is used to supply at least two kinds of powder by gravity, and the powder supplied by the powder supply unit is received by the powder weighing unit. The powder weighing unit weighs the weight of the received at least two kinds of powder respectively and in real time, and transmits the weight signal of each kind of powder to the control system. When the weight of any one kind of powder received by the control system reaches a preset value, the control system controls the powder supply unit to stop the supply of the kind of powder. Thus, under the control of the control system on the powder supply unit and the powder weighing unit, the online weighing and real-time adjustment of the at least two kinds of powder can be realized, the weight of each kind of powder can be controlled individually according to the preset value, the weight of each kind of powder can be accurately controlled, the proportion of the powder can be adjusted in real time, and the effect of additive manufacturing is improved. When the weight of each kind of powder received by the control system reaches the preset value, the powder weighing unit delivers the weighed powder to the powder mixing unit, and the control system controls the powder mixing unit to mix the at least two kinds of powder. Then, the control system controls the powder mixing unit to deliver the mixed powder according to the actual demand. By using the laser additive powder feeding device, on the one hand, the powder supply unit and the powder weighing unit can supply and weigh multiple kinds of powder synchronously, which can improve the efficiency of additive manufacturing compared with the separate weighing of multiple kinds of powder in the prior art; on the other hand, after the powder mixing unit receives the powder delivered by the powder weighing unit, the powder supply unit and the powder weighing unit can supply and weigh the powder synchronously when the powder mixing unit mixes the powder or outputs the powder, so that the supply of the powder is ensured, and the efficiency of additive manufacturing is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0007] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0008] Figure 1 A structural schematic diagram of the laser additive powder feeding device provided by the embodiment of the application;

[0009] Figure 2 A structural schematic diagram of the powder supply unit provided by the embodiment of the application;

[0010] Figure 3 A partial cross-sectional schematic diagram of the powder supply unit provided by the embodiment of the application Figure 1 ;

[0011] Figure 4 A partial cross-sectional schematic diagram of the powder supply unit provided by the embodiment of the application Figure 2 ;

[0012] Figure 5 A position relationship schematic diagram of the pressing assembly and the collar provided by the embodiment of the application;

[0013] Figure 6 A structural schematic view of the vibration powder feeding assembly provided for the embodiment of the present application;

[0014] Figure 7 A structural schematic view of the powder weighing assembly provided for the embodiment of the present application;

[0015] Figure 8 A structural schematic view of the powder mixing unit provided for the embodiment of the present application;

[0016] Figure 9 A structural schematic view of the air inlet pipe provided for the embodiment of the present application;

[0017] Figure 10 A structural schematic view of the air outlet pipe provided for the embodiment of the present application.

[0018] Reference signs:

[0019] 1 - a bearing frame, 11 - a powder feeding platform, 12 - a powder mixing platform, 2 - a powder supply unit, 21 - a powder storage cylinder,

[0020] 211 - a clamping ring, 22 - a first housing, 221 - a first cavity, 222 - a first limiting frame,

[0021] 23 - a sealing valve cap, 24 - a second housing, 241 - a supporting column, 242 - a powder falling nozzle,

[0022] 25 - a vibration powder feeding assembly, 251 - a vibration groove, 252 - a vibrator, 26 - a pressing assembly,

[0023] 261 - a supporting frame, 262 - a buckle, 263 - a second spring, 27 - a guide rod, 28 - a first spring,

[0024] 3 - a powder weighing unit, 31 - a weighing hopper, 32 - a weighing device, 4 - a powder mixing unit, 41 - a powder mixing tank,

[0025] 42 - a stirring assembly, 421 - a driving motor, 422 - a fan blade, 43 - an air inlet assembly,

[0026] 431 - an air inlet pipe, 4311 - a blowing hole, 432 - a first control valve, 433 - a flow meter,

[0027] 44 - an air outlet assembly, 441 - an air outlet pipe, 4411 - an air outlet hole, 442 - a second control valve,

[0028] 45 - a rotating assembly, 451 - a driving member, 452 - a driving gear, 453 - a driven gear. DETAILED DESCRIPTION

[0029] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0030] It should be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] In addition, the terms "first", "second" are only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited. The meaning of "several" is one or more, unless otherwise explicitly specified and limited.

[0032] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0033] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] Reference is made to Figure 1As shown, the embodiment of the present application provides a laser additive powder feeding device, which comprises a bearing frame 1, a powder supply unit 2, a powder weighing unit 3, a powder mixing unit 4 and a control system. The powder supply unit 2 is arranged on the bearing frame 1, and is used to supply at least two kinds of powder by gravity. The powder weighing unit 3 is arranged on the bearing frame 1, and is in communication with the powder supply unit 2, and is used to receive the powder and weigh the at least two kinds of powder respectively. The powder mixing unit 4 is in communication with the powder weighing unit 3, and is used to receive, mix and output the at least two kinds of powder weighed by the powder weighing unit 3. The control system is electrically connected with the powder supply unit 2, and is used to control the powder supply unit 2 to start or stop supplying the powder. The control system is electrically connected with the powder weighing unit 3, and is used to receive the weight signals of the at least two kinds of powder weighed by the powder weighing unit 3 respectively, and control the powder supply unit 2 to stop supplying the powder when the weight of any one kind of powder weighed by the powder weighing unit 3 reaches a preset value. The control system is also electrically connected with the powder mixing unit 4, and is used to control the powder mixing unit 4 to start or stop mixing the at least two kinds of powder, and control the powder mixing unit 4 to output the mixed powder.

[0035] In the technical solution, the laser additive powder feeding device comprises a bearing frame 1, a powder supply unit 2, a powder weighing unit 3, a powder mixing unit 4 and a control system. The powder supply unit 2 is used to supply at least two kinds of powder by gravity. The powder supplied by the powder supply unit 2 is received by the powder weighing unit 3. The powder weighing unit 3 weighs the weight of the received at least two kinds of powder respectively and in real time. That is, the powder weighing unit 3 receives the at least two kinds of powder supplied by the powder supply unit 2, weighs the weight of the received at least two kinds of powder at the same time, and transmits the weight signal of each kind of powder to the control system. When the weight of any kind of powder received by the control system reaches a preset value, the control system controls the powder supply unit 2 to stop the supply of the kind of powder. In this way, under the control of the control system on the powder supply unit 2 and the powder weighing unit 3, the online weighing and real-time adjustment of the at least two kinds of powder can be realized. The weight of each kind of powder is controlled individually according to the preset value, the weight of each kind of powder can be accurately controlled, the proportion of the powder can be adjusted in real time, and the effect of additive manufacturing is improved. When the weight of each kind of powder received by the control system reaches the preset value, the powder weighing unit 3 delivers the weighed powder to the powder mixing unit 4, and the control system controls the powder mixing unit 4 to mix the at least two kinds of powder. Then, the control system controls the powder mixing unit 4 to deliver the mixed powder according to actual needs. By using the laser additive powder feeding device, on the one hand, the powder supply unit 2 and the powder weighing unit 3 can supply and weigh multiple kinds of powder synchronously, which can improve the efficiency of additive manufacturing compared with the separate weighing of multiple kinds of powder in the prior art. On the other hand, after the powder mixing unit 4 receives the powder delivered by the powder weighing unit 3, the powder mixing unit 4 mixes the powder or outputs the powder, and the powder supply unit 2 and the powder weighing unit 3 can supply and weigh the powder synchronously to ensure the supply of the powder, and further improve the efficiency of additive manufacturing.

[0036] In specific implementation, the powder supply unit 2 can supply at least two kinds of powder at the same time. The number of kinds of powder supplied by the powder supply unit 2 is not limited here and can be set according to actual conditions. For example, the powder supply unit 2 can supply two, three, four or more kinds of powder at the same time, and the actual needs of cladding materials are selected and set. The powder weighing unit 3 receives the multiple kinds of powder delivered by the powder supply unit 2, weighs the multiple kinds of powder respectively, and transmits the weight signal of each kind of powder to the control system in the form of a signal. The control system compares the received weight signal with the preset value of each kind of powder. As the amount of powder received by the powder weighing unit 3 increases, when the weight of any kind of powder reaches the preset value, the control system controls the powder supply unit 2 to stop the supply of the kind of powder. In this way, the supply amount of each kind of powder can be accurately controlled.

[0037] In a possible implementation manner, as shown in Figures 2 to 7As shown, the powder supply unit 2 comprises at least two powder storage cartridges 21, a sealing valve cap 23, a second shell 24 and a vibration powder feeding assembly 25. The powder storage cartridges 21 are used for storing powder, and the outlet ends of the powder storage cartridges 21 are connected with a first shell 22. The first shell 22 has oppositely arranged first and second ends, and the first end is connected to the outlet ends of the powder storage cartridges 21. The first shell 22 has a first cavity 221 extending from the first end to the second end, and the outlet ends of the powder storage cartridges 21 are in communication with the first cavity 221, so that the materials contained in the powder storage cartridges 21 can be conveyed to the first cavity 221 through the outlet ends. The sealing valve cap 23 is arranged in the first cavity 221. The sealing valve cap 23 has oppositely arranged third and fourth ends, and the inner wall of the first cavity 221 has a limiting surface near the second end. The limiting surface is used to prevent the sealing valve cap 23 from falling off from the second end, so that the sealing valve cap 23 is limited in the first cavity 221. The sealing valve cap 23 has a sealing position and a release position relative to the first shell 22. When the sealing valve cap 23 is supported on the limiting surface, the sealing valve cap 23 is in the sealing position, and the fourth end of the sealing valve cap 23 is in sealing contact with the limiting surface. At this time, the materials in the first cavity 221 can be prevented from flowing out through the second end. When the sealing valve cap 23 is separated from the limiting surface, the sealing valve cap 23 is in the release position.

[0038] Meanwhile, the first shell 22 is provided with a first limiting frame 222, and the first limiting frame 222 is provided with a limiting hole matched with the third end, and the third end is movably arranged through the limiting hole. The second shell 24 is arranged on the bearing frame 1, and the second shell 24 is sleeved outside the first shell 22. The second shell 24 is provided with a supporting column 241 for supporting and lifting the sealing valve cap 23, so that the sealing valve cap 23 is in the release position. When the second shell 24 is sleeved outside the first shell 22, the supporting column 241 arranged in the second shell 24 can support and lift the sealing valve cap 23, so that the sealing valve cap 23 is separated from the limiting surface, and the materials in the first cavity 221 can be output through the second end, so as to realize the conveying of the materials. The end of the second shell 24 away from the powder storage cartridges 21 is provided with a powder falling nozzle 242. The vibration powder feeding assembly 25 comprises at least two vibration grooves 251 and at least two vibrators 252. The vibration grooves 251 are in communication with the powder falling nozzle 242, and each vibration groove 251 is used for receiving one kind of powder. The vibrators 252 are arranged on the powder feeding platform 11 of the bearing frame 1, and the vibration grooves 251 are fixedly installed on the vibrators 252. The vibrators 252 control the vibration of the corresponding vibration grooves 251, so that the powder received in the vibration grooves 251 falls from one end of the vibration grooves 251. The control system is electrically connected with the vibrators 252, and is used for controlling the start and stop of the vibration of the vibration grooves 251 and the vibration frequency of the vibration grooves.

[0039] In practice, the number of vibration grooves 251, vibrators 252, powder storage cylinders 21, sealing valve caps 23, and second housings 24 corresponds to the type of powder and is one-to-one. Vibration grooves 251 are located directly below powder discharge nozzles 242. Vibration grooves 251 receive the powder discharged from the corresponding discharge nozzles 242, and vibrators 252 control the vibration of the corresponding vibration grooves 251. The discharge nozzles 242 can be cylinders with an inner diameter of 10mm. If the inner diameter of the discharge nozzles 242 is too large, the powder will fall too quickly, causing excessive force on the vibration grooves 251. The outlet shape of the discharge nozzles 242 is consistent with the inner wall shape of the vibration grooves 251, both being "V"-shaped. Using a "V"-shaped vibration groove 251 can improve the powder's convergence and the accuracy of powder delivery. Meanwhile, the distance between the outlet end of the powder dispensing nozzle 242 and the vibration groove 251 can be 5mm-10mm. This way, the vibration groove 251 will not fail to vibrate due to too small a distance, and the powder will overflow from the side wall of the vibration groove 251 due to too large a distance. At the same time, too large a distance will also reduce the timeliness of the powder supply shutdown when the weight of the powder weighed by the downstream powder weighing unit 3 reaches the preset value, resulting in a slow response.

[0040] In the embodiment provided by the present invention, the first limiting frame 222 is provided with a limiting hole that cooperates with the third end. The third end moves through the limiting hole. When the sealing valve cap 23 switches between the sealing position and the releasing position, that is, when the sealing valve cap 23 moves towards and away from the second end, the sealing valve cap 23 can move along the axial direction of the limiting hole. The sealing valve cap 23 cooperates with the limiting hole, which plays a stable guiding role in the movement of the sealing valve cap 23.

[0041] like Figure 4 As shown, the sealing valve cap 23 can be a cylindrical structure. A guide rod 27 is provided at the third end of the sealing valve cap 23. The end of the guide rod 27 furthest from the third end moves through the limiting hole. The diameter of the guide rod 27 is smaller than the outer diameter of the sealing valve cap 23. A first spring 28 is sleeved on the guide rod 27. The two ends of the first spring 28 elastically act on the first limiting frame 222 and the third end of the sealing valve cap 23, respectively, to apply a force close to the limiting surface to the sealing valve cap 23. Thus, when the first housing 22 is removed from the second housing 24 and the sealing valve cap 23 detaches from the support column 241, the first spring 28 can force the sealing valve cap 23 to move towards the second end of the first housing 22, making the sealing valve cap 23 make sealing contact with the limiting surface, improving the sealing performance between the sealing valve cap 23 and the limiting surface, and preventing material leakage.

[0042] In actual application, when the powder storage cylinder 21 needs to be detached, the powder storage cylinder 21 can be directly taken off from the second shell 24 together with the first shell 22. When the supporting column 241 is separated from the sealing valve cap 23, the sealing valve cap 23 moves to the direction close to the second end under the action of the self-gravity and the first spring 28, so that the sealing valve cap 23 is supported by the limiting surface, the sealing valve cap 23 is switched from the release position to the sealing position, the fourth end of the sealing valve cap 23 is in sealing contact with the limiting surface, so that the material is blocked and limited in the first cavity 221, and the material can be prevented from spilling, thereby avoiding the waste of the material. In this way, the residual powder in the powder storage cylinder 21 cannot leak out, and the recycling of the residual material in the powder storage cylinder 21 is facilitated. When the powder storage cylinder 21 is installed after being filled with the material, the material cannot spill from the powder storage cylinder 21, and the powder storage cylinder 21 is convenient and reliable to install. When the powder storage cylinder 21 is installed, the first shell 22 is directly sleeved in the second shell 24, at this time, the supporting column 241 supports and lifts the sealing valve cap 23, so that the sealing valve cap 23 is separated from the limiting surface, and the sealing valve cap 23 is in the release position, thereby realizing the material conveying. In this way, the powder supply unit 2 provided by the embodiment of the present application can realize the quick disassembly of the powder storage cylinder 21 for supplementing the material, and can improve the disassembly efficiency of the powder storage cylinder 21 while avoiding the spilling of the material and saving the cost.

[0043] Exemplarily, the vibrator 252 is an electromagnetic vibrator. The power of the electromagnetic vibrator can be 15 watts, the load can be 1.5 kilograms, the amplitude can be 1.0 mm, the conveying distance can be 250 mm, and the length of the vibration groove 251 can be controlled within 250 mm, which is not limited here. Different specifications of electromagnetic vibrators can be selected for different application occasions. The vibration frequency of the vibrator 252 determines the real-time powder conveying amount, and the vibration frequency and time of the vibrator 252 are controlled by the programmable control system.

[0044] In an example, as shown in Figures 2 to 5 The outer wall of the powder storage cylinder 21 is provided with a ring 211, and the powder supply unit 2 further comprises a pressing assembly 26 arranged on the carrier 1. The pressing assembly 26 cooperates with the ring 211 and is used to press and limit the powder storage cylinder 21 on the carrier 1. In this way, after the powder storage cylinder 21 is installed on the carrier 1 through the first shell 22 and the second shell 24, the pressing assembly 26 is pressed and limited on the carrier 1 through the ring 211, which can improve the firmness of the powder storage cylinder 21 arranged on the carrier 1, avoid the shaking of the powder storage cylinder 21 and the shift of the position, and facilitate the stable conveying of the powder.

[0045] Specifically, the pressing assembly 26 includes a support frame 261, a buckle 262, and a second spring 263. The support frame 261 is fixedly mounted on the carrier frame 1, the buckle 262 is movably mounted on the support frame 261, and the two ends of the second spring 263 elastically act on the buckle 262 and the carrier frame 1 respectively, so that the end of the buckle 262 near the powder storage cylinder 21 presses against the retaining ring 211. Figure 5 As shown, the support may include two opposing support plates, with one end of the buckle 262 rotatably mounted on the two support plates. The second spring 263 is in a stretched state, with one end connected to the support frame 1 and the other end connected to the buckle 262. During the process of installing the powder storage cylinder 21 onto the support frame 1, the retaining ring 211 contacts the buckle 262 and presses the buckle 262, causing the end of the buckle 262 near the powder storage cylinder 21 to rotate towards the support frame 1. The powder storage cylinder 21 continues to move towards the support frame 1 and further presses the buckle 262 until the second housing 24 is fitted over the first housing 22. The end of the buckle 262 near the powder storage cylinder 21 is located on the side of the retaining ring 211 away from the support frame 1 and is pressed onto the retaining ring 211 under the action of the second spring 263, firmly locking the powder storage cylinder 21 and preventing the buckle 262 from springing back and escaping.

[0046] As an optional feature, the vibratory powder feeding assembly 25 also includes a shock-absorbing elastic element, which is disposed between the corresponding vibrator 252 and the support frame 1. Each vibrator 252 is equipped with a corresponding shock-absorbing elastic element to reduce the interference caused by the vibration of the vibrator 252 on the powder feeding platform 11 of the support frame 1. Specifically, the shock-absorbing elastic element can be a compression spring pad or a rubber soft pad. Compression spring pads or rubber soft pads have a simple structure and good shock absorption effect, which can ensure the effect of the shock-absorbing elastic element in reducing the interference between the vibrator 252 and the powder feeding platform 11.

[0047] As an optional configuration, the powder weighing unit 3 includes at least two weighing hoppers 31 and at least two weighing devices 32. The weighing hoppers 31 are fixedly connected to their corresponding weighing devices 32. The weighing hoppers 31 are positioned below the powder supply unit 2. Each weighing hopper 31 receives one type of powder from the powder supply unit 2. The weighing device 32 is mounted on the support frame 1 and is used to weigh the powder within the weighing hopper 31. The control system is electrically connected to the weighing device 32, receiving electrical signals transmitted by the weighing device 32 and controlling the start and stop of the vibrator 252 of the powder supply unit 2, as well as the powder supply frequency of the powder supply unit.

[0048] Specifically, the number of weighing hoppers 31 and weighing devices 32 corresponds to the type of powder, and they are one-to-one. For example, as shown... Figure 6 and Figure 7As shown, in the embodiment provided by the present application, the number of the weighing hoppers 31, the number of the weight scales 32, the number of the vibrating grooves 251 and the number of the vibrators 252 are all six, one powder storage cylinder 21 corresponds to one vibrating groove 251, one vibrator 252, one weighing hopper 31 and one weight scale 32, and then the number of the powder storage cylinders 21 is six. In the powder feeding process of additive manufacturing, first, according to the proportion of each powder, the preset powder weight required to be received by each weighing hopper 31 is stored in the control system, the powder in the powder storage cylinder 21 is first conveyed into the vibrating groove 251, then the control system controls the vibrator 252 to vibrate at a high vibration frequency, so that the vibrating groove 251 vibrates and drives the powder to vibrate, and the powder gradually falls from one end of the vibrating groove 251 to the corresponding weighing hopper 31, at this time, the powder feeding speed is fast, but the precision is low, the weight scale 32 real-time weighs the weight of the powder in the weighing hopper 31 and transmits the powder weight signal to the control system, when the weight of the powder in a certain weighing hopper 31 approaches the preset powder weight of the weighing hopper 31, for example, when the weight of the powder in the weighing hopper 31 is 90% of the preset powder weight of the weighing hopper 31, the control system controls the corresponding vibrator 252 to vibrate at a lower vibration frequency, the vibration frequency of the corresponding vibrating groove 251 slows down, and then the powder flow speed is reduced to complete the remaining 10% of the preset powder weight of the weighing hopper 31, at this time, the powder feeding speed is slow, but the precision is high. When the weight of the powder in a certain weighing hopper 31 is equal to the preset powder weight of the weighing hopper 31, the control system controls the corresponding vibrator 252 to stop vibrating, until the weight of the powder in all weighing hoppers 31 reaches the corresponding preset powder weight, then the powder in all weighing hoppers 31 is flowed into the powder mixing unit 4, and then the above steps are repeated to perform a new round of powder feeding and weighing.

[0049] As can be seen from the structure and specific implementation process of the vibrating powder feeding assembly 25 and the powder weighing unit 3, the vibrator 252 drives the vibrating groove 251 to vibrate, and then drives the powder to vibrate and flow into the weighing hopper 31, the powder is always in vibration during the powder feeding process, and the control system can control the vibration frequency of the vibrator 252 to adjust the powder feeding speed of each powder. The weight scale 32 can real-time monitor the weight of the powder in the weighing hopper 31 and transmit it to the control system, and stop the powder feeding by controlling the vibrator 252 to stop, realizing the online weighing of multiple powders. Compared with the prior art, the powder is driven to vibrate and flow into the weighing hopper 31 by the vibrating groove 251, and the powder is always in a vibrating state during the powder feeding process, which avoids powder agglomeration and ensures uniform powder feeding of light and fine powders. The weight scale 32 can real-time monitor the weight of the powder in the weighing hopper 31, realizing the online weighing of multiple powders, and then improving the proportioning accuracy of different powders. In addition, the control system can real-time adjust the preset powder weight of different weighing hoppers 31 to real-time adjust the proportioning of multiple powders.

[0050] In some embodiments, referring to Figure 6 , the center of the powder feeding platform 11 is provided with a first through hole, the top of the weighing hopper 31 passes through the first through hole and is arranged below the powder flow outlet of the corresponding vibration groove 251, and the height gap between the top inlet of the weighing hopper 31 and the powder flow outlet of the corresponding vibration groove 251 is 5-20 mm. For example, the height gap between the top inlet of the weighing hopper 31 and the powder flow outlet of the corresponding vibration groove 251 is 5 mm, 10 mm, 15 mm, 20 mm, etc. By arranging the first through hole in the center of the powder feeding platform 11, the top of the weighing hopper 31 passes through the first through hole and the top inlet of the weighing hopper 31 is located below the powder flow outlet of the corresponding vibration groove 251, so that all the powder flowing down during the vibration of the vibration groove 251 enters the corresponding weighing hopper 31, avoiding the splashing loss of the powder. In addition, there is a certain height gap between the top inlet of the weighing hopper 31 and the powder flow outlet of the corresponding vibration groove 251, which prevents the vibration groove 251 and the weighing hopper 31 from colliding and interfering with each other during vibration, and the height gap is between 5 mm and 20 mm, preventing the gap from being too large to cause the powder to splash during the vibration of the powder, resulting in the waste of the powder.

[0051] In a possible implementation, referring to Figure 8 , the powder mixing unit 4 includes a powder mixing tank 41, a stirring assembly 42, an air inlet assembly 43 and an air outlet assembly 44, the powder mixing tank 41 is rotatably installed on the powder mixing platform 12 of the carrying frame 1, and the stirring assembly 42, the air inlet assembly 43 and the air outlet assembly 44 are all installed on the powder mixing platform 12. The powder mixing tank 41 is in communication with the powder weighing unit 3, specifically, the feeding port of the powder mixing tank 41 is in communication with the powder outlet of the corresponding weighing hopper 31, so that the powder mixing tank 41 can receive at least two kinds of powder. And in specific implementation, a gap of 2-4 mm is left between the powder outlet of the weighing hopper 31 and the feeding port of the powder mixing tank 41 in the vertical direction, avoiding interference with the weighing. In addition, the diameter of the powder outlet of the weighing hopper 31 is smaller than the diameter of the feeding port of the corresponding powder mixing tank 41, and the difference is in the range of 2-4 mm, avoiding the low speed of powder discharge when the powder outlet of the weighing hopper is small, and avoiding the risk of powder residue. The stirring assembly 42 is installed on the powder mixing platform 12 of the carrying frame 1, and is used for stirring at least two kinds of powder in the powder mixing tank 41. The air inlet assembly 43 is arranged on the carrying frame 1, and is used for introducing gas into the powder mixing tank 41. The air outlet assembly 44 is arranged on the carrying frame 1, and is used for guiding the gas and the mixed powder in the powder mixing tank 41 out.

[0052] When the above technical solution is adopted, after the powder weighing unit 3 conveys the weighed powder to the mixing tank 41 through the powder outlet of the weighing hopper 31 and the inlet of the mixing tank 41, and mixing is required, the stirring component 42 can stir the powder in the mixing tank 41, and the air inlet component 43 can introduce gas into the mixing tank 41 to suspend the powder. By mixing the powder together with the stirring component 42 and the air inlet component 43, the mixing time can be reduced and the mixing effect can be improved. Secondly, after the air inlet component 43 introduces gas into the mixing tank 41, the powder is suspended in the air under the action of the gas. At this time, the stirring component 42 can stir the surrounding gas, so as to form a vortex. The fluid structure, combined with the gas introduced through the air inlet component 43, further reduces powder mixing time and improves mixing effect, resulting in more uniform powder mixing and thus better performance of the laser additive manufacturing process. Third, the air inlet component 43 and the air outlet component 44 work together to remove powder from the powder mixing tank 411. After gas is introduced through the air inlet component 43, the gas flows through the powder mixing tank 41 and into the air outlet component 44, where it is then discharged. The gas carries the powder out as a carrier gas, allowing it to be discharged in a more uniform state for the next process, further improving the performance of the laser additive manufacturing process. Additionally, the gas introduced into the powder mixing tank 41 through the air inlet component 43 also cleans the powder within the tank, enabling the powder mixing device to achieve a self-cleaning function.

[0053] like Figure 8 As shown, the stirring assembly 42 further includes a drive motor 421 and a fan blade 422. The drive motor 421 is connected to the fan blade 422, which is disposed inside the powder mixing tank 41. The drive motor 421 drives the fan blade 422 to rotate, thereby stirring the powder inside the powder mixing tank 41. The drive motor 421 is mounted on the powder mixing platform 12, and the fan blade 422 is located inside the powder mixing tank 41 and connected to the motor shaft of the drive motor 421. The drive motor 421 can drive the fan blade 422 to rotate. When the drive motor 421 drives the fan blade 422 to rotate, it can drive the surrounding fluid to move, forming fluid structures such as swirling and eddy currents. Under the action of this fluid structure and the gas introduced by the air intake assembly 43, the powder mixing time can be further reduced, the powder mixing effect can be improved, and the powder mixing can be made more uniform, thereby improving the performance of the workpiece formed by laser additive manufacturing.

[0054] In some embodiments, such as Figure 8As shown, the fan blades 422 are arranged at the center of the mixing tank 411, and the fan blades 422 include a plurality of blades evenly distributed along the circumference thereof. For example, the driving motor 421 has a rotating speed of no less than 10,000 revolutions per minute, and the blades have an inclination angle of 35 degrees. For example, the volume of the mixing tank 41 in the embodiment is 3.4 liters, the diameter of the blades is at least 80 mm, the number of the blades is at least three, and the fan blades 422 can form a better cyclone effect after running for 2 minutes. With the structure, when the fan blades 422 are arranged at the center of the mixing tank 41, the cyclone and vortex effects are better, the powder is uniformly diffused in the mixing tank 41, and the powder mixing is more uniform, thereby improving the powder mixing effect. When the plurality of blades are evenly distributed along the circumference for stirring, the cyclone and vortex effects are better, the powder is more effectively dusted, dispersed, and mixed more uniformly, and the powder mixing effect is improved.

[0055] As an optional mode, the air inlet assembly 43 includes an air inlet pipe 431, a first control valve 432, and a flow meter 433. One end of the air inlet pipe 431 extends into the mixing tank 41, and the other end is connected with an external air supply device. The control system is electrically connected with the first control valve 432 for closing or opening the air inlet pipe 431. The flow meter 433 is arranged on the pipeline of the air inlet pipe 431 for measuring the flow rate of the gas flowing through the air inlet pipe 431. When air is needed, the control system controls the first control valve 432 to open the air inlet pipe 431, and the gas from the external air supply device flows into the mixing tank 41 through the air inlet pipe 431 for air supply. When air is not needed, the control system controls the first control valve 432 to close the air inlet pipe 431, and the gas from the external air supply device is cut off when passing through the air inlet pipe 431, and no gas flows into the mixing tank 41. The flow rate of the gas in the air inlet pipe 431 can be calculated by the flow meter 433, and the air supply amount in the mixing tank 41 can be accurately controlled. For example, the flow meter 433 can be a mechanical flow meter 433 or an electronic flow meter 433, which is not limited herein.

[0056] Similarly, the air outlet assembly 44 includes an air outlet pipe 441 and a second control valve 442. One end of the air outlet pipe 441 is located in the mixing tank 41, and the other end extends out of the mixing tank 41. The control system is also electrically connected with the first control valve 432 for closing or opening the air outlet pipe 441. At this time, when the powder in the mixing tank 41 needs to be mixed or the mixing tank 41 needs to be cleaned, the first control valve 432 opens the air inlet pipe 431, and the second control valve 442 closes the air outlet pipe 441, so that the gas in the air inlet pipe 431 flows into the mixing tank 41. When the powder needs to be sent out, the second control valve 442 opens the air outlet pipe 441, the gas in the air inlet pipe 431 flows through the mixing tank 41, and the powder-gas mixture in the mixing tank 41 is sent out from the air outlet pipe 441. For example, the control valve can be an electromagnetic valve or a pneumatic valve.

[0057] In some embodiments, the powder mixing unit 4 further comprises a rotating assembly 45 connected with the powder mixing tank 41 for driving the powder mixing tank 41 to rotate relative to the bearing frame 1. The control system is connected with the rotating assembly 45 for controlling the rotation of the powder mixing tank 41. The powder mixing tank 41 is rotatably connected with the powder mixing platform 12 through a bearing, and the powder mixing tank 41 is sealingly connected with the powder mixing platform 12. The rotating assembly 45 can drive the powder mixing tank 41 to rotate forward and reverse, and by controlling the forward and reverse rotation of the powder mixing tank 41, the powder mixing tank 41 can be swung, so that the cleaning effect of the powder mixing tank 41 is better. Specifically, when the powder mixing tank 41 rotates, the stirring assembly 42, the air inlet assembly 43 and the air outlet assembly 44 do not rotate with the rotation of the powder mixing tank 41, and the powder mixing tank 41 can further mix the powder when rotating, so as to further improve the mixing effect of the powder. At the same time, the air inlet assembly 43 can blow and clean the powder mixing tank 41 once a week, improving the cleaning effect of the powder mixing tank 41. In addition, it should be noted that the inner walls of the containers through which the powder of the powder storage cylinder 21, the weighing hopper 31 and the powder mixing tank 41 pass are all mirror polished, which maximizes the reduction of powder residue.

[0058] As shown in Figure 8 Further, the rotating assembly 45 comprises a driving member 451, a driving gear 452 and a driven gear 453. The driving member 451 is in transmission connection with the driving gear 452, and the driving gear 452 and the driven gear 453 are in engagement. The driven gear 453 is fixed on the powder mixing tank 41 or is in an integral structure with the powder mixing tank 41. The driving member 451 drives the driving gear 452 to rotate, and the driving gear 452 drives the driven gear 453 to rotate when rotating. The driven gear 453 drives the powder mixing tank 41 to rotate relative to the powder mixing platform 12 when rotating. For example, the driving member 451 can be a motor or a pneumatic cylinder. With this structure, the driven gear 453 can be driven to rotate by driving the driving gear 452 to rotate by the driving member 451, and then the powder mixing tank 41 can be driven to rotate relative to the powder mixing platform 12.

[0059] Further, as shown in Figure 9As shown, the pipe wall of the air inlet pipe 431 is provided with a plurality of blowing holes 4311, which are directed to the inner wall of the powder mixing tank 41 to blow the powder on the inner wall of the powder mixing tank 41. For example, the shape of the air inlet pipe 431 matches the shape of the inner wall of the powder mixing tank 41. For example, in the embodiment, the powder mixing tank 41 includes a main body portion, a transition portion and a bottom plate connected in sequence, the transition portion is arranged obliquely relative to the main body portion, the air inlet pipe 431 includes an upper pipe portion and a lower pipe portion, the lower pipe portion is arranged obliquely relative to the upper pipe portion, the upper pipe portion is arranged parallel to the main body portion, and the lower pipe portion is arranged parallel to the transition portion. For example, a plurality of blowing holes 4311 are arranged on the upper pipe portion and the lower pipe portion. For example, the diameter of the blowing hole 4311 is 1.5 mm, which can avoid the risk of being blocked due to too small diameter and poor air inlet effect due to too large diameter. With this structure, the inner wall of the powder mixing tank 41 can be blown through the plurality of blowing holes 4311, so that the cleaning effect of the air inlet assembly 433 can be improved, and the self-cleaning function of the powder mixing device can be improved.

[0060] Referring to Figure 10 The pipe wall of the air outlet pipe 441 is provided with a plurality of exhaust holes 4411. For example, the air outlet pipe 441 is a straight pipe structure parallel to the axis of the powder mixing tank 41, the air outlet pipe 441 is provided with a plurality of exhaust holes 4411 arranged in the vertical direction in sequence, and the air outlet pipe 441 is provided with a plurality of rows of exhaust holes 4411 uniformly distributed in the circumferential direction of the air outlet pipe 441. The distance between the air outlet pipe 441 and the inner wall of the powder mixing tank 41 is about 20 mm, which can make the powder-gas mixture in the powder mixing tank 41 pass through the exhaust holes 4411 more uniformly; for example, the diameter of the exhaust hole 4411 is 1.5 mm, which can avoid the risk of being blocked due to too small diameter and poor exhaust effect due to too large diameter. With this structure, the powder-gas mixture in the powder mixing tank 41 can be exhausted more uniformly through the plurality of exhaust holes 4411, so that the powder discharged from the air outlet is more uniform, and the performance of the workpiece formed by laser additive manufacturing is better.

[0061] In an optional manner, the bottom of the powder mixing tank 41 is provided with an opening, the powder mixing tank 41 is provided with a first valve at a position corresponding to the opening, and the control system is electrically connected with the first valve to close or open the opening. For example, the first valve can be a butterfly valve. With this structure, the powder in the powder mixing tank 41 can be discharged in two ways, one is that the powder-gas mixture is discharged from the air outlet pipe 441 in the form of carrier gas through the cooperation of the air inlet assembly 43 and the air outlet assembly 44, and the other is that the powder is discharged in the form of free falling powder through the opening in the bottom of the powder mixing tank 41 under the action of gravity, so that the cleanliness of the powder mixing tank 41 is higher, and the self-cleaning effect of the powder mixing device is improved.

[0062] As Figure 8As shown, further, the powder mixing unit 4 further comprises a vibration motor installed on the powder mixing tank 41. With this structure, the powder mixing unit 4 can be vibrated by the vibration motor, and the powder in the powder mixing tank 41 can be further reduced, and the cleaning effect of the powder mixing device can be improved.

[0063] It should be noted that in actual implementation, a second valve is arranged at the position of the powder falling nozzle 242, and the second valve is electrically connected with the control system to prevent or release the powder in the powder storage cylinder 21 from falling through the powder falling nozzle 242. A third valve is arranged at the position of the powder outlet of the weighing hopper 31, and the third valve is electrically connected with the control system to control the on-off of the powder outlet of the weighing hopper 31. Meanwhile, a fourth valve is installed at the position of the powder inlet of the powder mixing tank 41, and the fourth valve is electrically connected with the control system to prevent or allow the powder mixing tank 41 to receive powder. The first valve, the second valve, the third valve and the fourth valve can all be butterfly valves.

[0064] In actual situation, initially, the second valve can be in an open state, and the third valve can be in a closed state. When the second shell 24 is sleeved outside the first shell 22, the supporting column 241 supports and lifts the sealing valve cap 23 to make the sealing valve cap 23 disengage from the limiting surface, so that the material in the first cavity 221 is output through the second end and the powder falling nozzle 242. The powder falls into the vibration groove 251 under the action of its own gravity, and the powder received by the vibration groove 251 falls from one end of the vibration groove under the vibration action of the corresponding vibrator 252. The powder is received by the weighing hopper 31, and the weight of the powder in the weighing hopper 31 is weighed in real time by the weighing device 32. When the weight signal of the weighing device 32 received by the control system reaches a preset value, the control system controls the second valve of the corresponding powder to be closed, and the corresponding vibrator 252 is stopped from vibrating. When the weights of the powders of multiple kinds all reach the preset value, the control system controls the third valve and the fourth valve to be opened. At this time, the powder in the weighing hopper 31 can fall into the powder mixing tank 41, and the supply of the powder is completed.

[0065] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, and all of these shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A laser additive manufacturing powder feeding device, characterized in that, include: Support frame; A powder supply unit is disposed on the support frame, and the powder supply unit is used to supply at least two kinds of powders by gravity. A powder weighing unit is disposed on the support frame; the powder weighing unit is connected to the powder supply unit and is used to receive the powder and weigh at least two kinds of the received powder respectively; A powder mixing unit, connected to the powder weighing unit, is used to receive, mix, and output at least two powders weighed by the powder weighing unit. The control system is electrically connected to the powder supply unit and is used to control the powder supply unit to start or stop supplying powder. The control system is also electrically connected to the powder weighing unit and is used to receive weight signals of at least two types of powder weighed by the powder weighing unit. When the weight of any one type of powder weighed by the powder weighing unit reaches a preset value, the control system controls the powder supply unit to stop supplying that type of powder. The control system is further electrically connected to the powder mixing unit and is used to control the powder mixing unit to start or stop mixing at least two types of powder and to control the powder mixing unit to output the mixed powder. The powder supply unit includes: At least two powder storage cylinders are provided for storing the powder; the outlet end of each powder storage cylinder is connected to a first housing, the first housing having a first end and a second end disposed opposite to each other, the first end being connected to the outlet end of the powder storage cylinder; the first housing has a first cavity extending from the first end to the second end. A sealing valve cap is disposed within the first cavity. The sealing valve cap has a third end and a fourth end disposed opposite to each other. A limiting surface is provided on the inner wall of the first cavity near the second end, and the limiting surface is used to prevent the sealing valve cap from falling off from the second end. The sealing valve cap has a sealing position and a release position relative to the first housing. When the sealing valve cap is supported by the limiting surface, the sealing valve cap is in the sealing position, and the fourth end of the sealing valve cap is in sealing contact with the limiting surface. When the sealing valve cap is detached from the limiting surface, the sealing valve cap is in the release position. A first limiting frame is provided inside the first housing, and the first limiting frame has a limiting hole that cooperates with the third end, and the third end moves through the limiting hole. A second housing is disposed on the support frame and sleeved outside the first housing. A support column is disposed inside the second housing to support and lift the sealing valve cap, so that the sealing valve cap is in the released position. A powder discharge nozzle is disposed at the end of the second housing away from the powder storage cylinder. A vibrating powder feeding assembly includes at least two vibrating grooves and at least two vibrators. The vibrating grooves are connected to the powder discharge nozzle, and each vibrating groove is used to receive one type of powder. The vibrators are disposed on the support frame and are used to control the vibration of the corresponding vibrating groove so that the powder received by the vibrating groove falls from one end of the vibrating groove. The control system is electrically connected to the vibrators and is used to control the start and stop of the vibration of the vibrating groove and to control the vibration frequency of the vibrating groove.

2. The laser additive powder feeding device according to claim 1, characterized in that, The outer wall of the powder storage cylinder is provided with a retaining ring, and the powder supply unit also includes a pressing component disposed on the support frame. The pressing component cooperates with the retaining ring to press the powder storage cylinder to the support frame.

3. The laser additive powder feeding device according to claim 1, characterized in that, The vibratory powder feeding assembly also includes a shock-absorbing elastic element, which is disposed between the corresponding vibrator and the support frame to eliminate and shield the interference caused to the support frame when the vibrator vibrates.

4. The laser additive powder feeding device according to claim 1, characterized in that, The powder weighing unit includes at least two weighing hoppers and at least two weighing devices. The weighing hoppers are fixedly connected to their corresponding weighing devices. The weighing hoppers are located below the powder supply unit. Each weighing hopper is used to receive one type of powder supplied by the powder supply unit. The weighing devices are located on the support frame and are used to weigh the powder in the weighing hoppers. The control system is electrically connected to the weighing devices and is used to receive electrical signals transmitted by the weighing devices and control the start and stop of the powder supply unit and the powder supply frequency of the powder supply unit.

5. The laser additive powder feeding device according to claim 1, characterized in that, The powder mixing unit includes: A powder mixing tank is rotatably mounted on the support frame. The powder mixing tank is connected to the powder weighing unit and is used to receive at least two kinds of powders. A stirring assembly, mounted on the support frame, is used to stir at least two of the powders in the mixing tank; An air intake assembly, disposed on the support frame, is used to introduce gas into the powder mixing tank; An exhaust assembly, located on the support frame, is used to exhaust the gas and mixed powder from the mixing tank.

6. The laser additive powder feeding device according to claim 5, characterized in that, The stirring assembly includes a drive motor and fan blades. The drive motor is connected to the fan blades, which are disposed inside the powder mixing tank. The drive motor drives the fan blades to rotate in order to stir the powder inside the powder mixing tank.

7. The laser additive powder feeding device according to claim 5, characterized in that, The air intake assembly includes an air intake pipe, a first control valve, and a flow meter. One end of the air intake pipe extends into the powder mixing tank, and the other end is used to connect to an external air supply device. The control system is electrically connected to the first control valve and is used to close or open the air intake pipe. The flow meter is installed on the air intake pipe and is used to measure the flow rate of the gas flowing through the air intake pipe. The air outlet assembly includes an air outlet pipe and a second control valve. One end of the air outlet pipe is located inside the powder mixing tank, and the other end extends to the outside of the powder mixing tank. The control system is also electrically connected to the first control valve for closing or opening the air outlet pipe.

8. The laser additive powder feeding device according to claim 7, characterized in that, The powder mixing unit also includes a rotating component connected to the powder mixing tank for driving the powder mixing tank to rotate relative to the support frame; the control system is connected to the rotating component for controlling the rotation and stopping of the powder mixing tank.

9. The laser additive powder feeding device according to claim 8, characterized in that, The air inlet pipe has multiple air blowing holes on its wall, which face the inner wall of the powder mixing tank to blow away the powder on the inner wall of the mixing tank; or, The exhaust pipe has multiple exhaust holes on its wall; or, The bottom of the mixing tank is provided with an opening, and a first valve is provided on the mixing tank at the position corresponding to the opening. The control system is electrically connected to the first valve and is used to close or open the opening.

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