Welding gun device based on additive manufacturing and fuse wire additive manufacturing system and method

Abstract

The invention discloses a welding gun device based on additive manufacturing and a fuse wire additive manufacturing system and method, and relates to the field of material processing. In the gun head, a shell is connected with the wire feeding mechanism, the shell is provided with a cavity and a feeding channel communicated with the cavity, the feeding channel, the wire feeding channel and the compression nozzle are coaxially arranged, an upper end opening of the feeding channel is communicated with a lower end opening of the wire feeding channel, and the compression nozzle is arranged at the lower end opening of the feeding channel. The at least two tungsten electrodes are arranged in the cavity and are connected with the shell, the at least two tungsten electrodes in the cavity are circumferentially and uniformly distributed in the circumferential direction of the feeding channel, and all the tungsten electrodes can be matched with the compression nozzle to generate plasma arcs when powered on; when the gun head generates the plasma arc, the part, located in the compression nozzle, of the welding wire is preheated, and the part, located below the compression nozzle, of the welding wire is heated and melted, so that the directional influence between a heat source and the welding wire in the additive manufacturing process can be reduced, the limiting influence on the shape of a formed part is reduced, and the fuse deposition efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material processing, in particular to a welding gun device based on additive manufacturing, a fused filament additive manufacturing system and method. BACKGROUND

[0002] Fused filament additive manufacturing is an additive manufacturing technology that builds three-dimensional entities by layer-by-layer melting deposition of filaments, which has the advantages of high material utilization and wide applicability. The heat source used in the fused filament additive manufacturing method includes laser, electron beam, electric arc, plasma arc, etc. During the additive manufacturing process, the spatial position between the heat source and the filament (or welding wire) has a great influence. Generally, the side-shaft wire feeding method is adopted, which limits the shape of the formed parts. At the same time, the deposition efficiency of the fused filament additive manufacturing is still one of the difficulties to be solved in the current additive manufacturing. SUMMARY

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a welding gun device based on additive manufacturing, a fused filament additive manufacturing system and method, which can reduce the directional influence between the heat source and the filament during the additive manufacturing process, reduce the limitation of the shape of the formed parts, and improve the deposition efficiency of the fused filament.

[0004] The first aspect of the present application provides a welding gun device based on additive manufacturing, comprising: a wire feeding mechanism provided with a wire feeding channel for the welding wire to move from top to bottom; a gun head comprising a shell, a tungsten electrode and a compression nozzle, the shell is connected with the wire feeding mechanism, the shell is provided with a cavity and a feeding channel, the feeding channel extends through along the up-down direction and communicates with the cavity, the feeding channel, the wire feeding channel and the compression nozzle are coaxially arranged, the upper end opening of the feeding channel communicates with the lower end opening of the wire feeding channel, the compression nozzle is arranged at the lower end opening of the feeding channel and connected with the shell, the tungsten electrode is arranged in the cavity, the tungsten electrode is provided with at least two and arranged uniformly in a circle along the circumference of the feeding channel, all the tungsten electrodes are configured to generate a plasma arc in cooperation with the compression nozzle when energized; wherein the gun head is configured to preheat the part of the welding wire located in the compression nozzle and heat and melt the part of the welding wire located below the compression nozzle when the plasma arc is generated.

[0005] The welding torch device based on additive manufacturing according to the first aspect of the present application has at least the following beneficial effects: when the wire feeding mechanism is in operation, the welding wire moves from top to bottom and sequentially passes through the wire feeding channel, the feeding channel and the compression nozzle, at this time, the torch head generates a plurality of plasma arcs in cooperation with the compression nozzle by the energized tungsten electrode, the plurality of plasma arcs are arranged in a circle about the welding wire, so that the plurality of plasma arcs can form a preheating field in the compression nozzle and effectively preheat the passing welding wire to speed up the melting speed of the welding wire, and the plurality of plasma arcs and the welding wire are output from the compression nozzle together, so that the welding wire can be rapidly melted above the co-melt pool under the continuous heating of the plurality of plasma arcs, thereby effectively improving the wire melting deposition efficiency; at the same time, the plurality of plasma arcs output from the compression nozzle can form a composite plasma arc beam and be arranged in a circle with the axis of the welding wire as the array center, and the welding wire maintains a vertical state during the additive manufacturing process, thereby reducing the influence caused by the inconsistency between the action direction of the heat source and the feeding direction of the welding wire and effectively reducing the limitation on the shape of the formed part.

[0006] In some embodiments of the present application, the tungsten electrode is provided with four tungsten electrodes which are uniformly arranged in a circle along the circumference of the feeding channel.

[0007] In some embodiments of the present application, the tungsten electrode is inclined from top to bottom to the feeding channel, and the tip of the tungsten electrode is located in the compression nozzle.

[0008] In some embodiments of the present application, the shell is provided with a gas flow channel, an air inlet and an air outlet which are in communication with the gas flow channel, the gas flow channel is inclined from top to bottom to the feeding channel, the air outlet is in communication with the feeding channel, and the outer circumference of each tungsten electrode is provided with a plurality of gas flow channels which are configured to allow argon gas to flow and form a protective layer for protecting the tungsten electrode.

[0009] In some embodiments of the present application, the wire feeding mechanism includes a wire feeding pipe and at least one pair of wire feeding wheels, the wire feeding pipe is provided with the wire feeding channel extending through in the up-down direction, and at least one pair of wire feeding wheels are configured to transport the welding wire during rotation so that the welding wire sequentially passes through the wire feeding channel and the feeding channel and extends downward from the compression nozzle.

[0010] In some embodiments of the present application, at least one pair of wire feeding wheels are arranged above the wire feeding channel, and at least one pair of wire feeding wheels form a conveying channel which is coaxially arranged and communicated with the wire feeding channel.

[0011] In some embodiments of the present application, the compression nozzle is provided with a water cooling channel, a water inlet and a water outlet which are in communication with the water cooling channel, and the water cooling channel is arranged along the circumference of the feeding channel.

[0012] The second aspect of the present application provides a fused filament fabrication system, comprising: The additive manufacturing-based welding gun device according to the first aspect of the present application; A motion device, a movable end of which is connected to the housing, and the motion device is configured to drive the additive manufacturing-based welding gun device to move along a deposition trajectory, so that the additive manufacturing-based welding gun device performs fused filament deposition work.

[0013] The fused filament fabrication system according to the second aspect of the present application has at least the following beneficial effects: during the process that the motion device drives the additive manufacturing-based welding gun device to move along the deposition trajectory to perform the fused filament deposition work, the multiple plasma arcs generated by the gun head can preheat the welding wire in the compression nozzle, promote the welding wire to melt faster, and help to improve the deposition efficiency. In addition, the multiple plasma arcs are uniformly distributed around the vertically descending welding wire, which can reduce the directional influence between the heat source and the welding wire during the additive manufacturing process, reduce the limitation on the shape of the formed part, and help to improve the additive manufacturing quality.

[0014] In some embodiments of the present application, the motion device is a multi-axis robot or a multi-axis linear module.

[0015] The third aspect of the present application provides a fused filament fabrication method, which is applied to the fused filament fabrication system according to the second aspect of the present application, and the fused filament fabrication method comprises the following steps: S1: three-dimensional modeling is performed on a target workpiece, and a three-dimensional model corresponding to an additive formed part is generated; S2: the three-dimensional model is subjected to layering processing, and additive path planning is performed on each layer to generate a deposition trajectory; S3: the pre-processed substrate is placed on a workbench; S4: the motion device drives the additive manufacturing-based welding gun device to move according to the deposition trajectory, the wire feeding mechanism and the gun head operate, multiple plasma arcs and the pre-processed welding wire are output from the compression nozzle, the multiple plasma arcs act on the surface of the substrate or the deposited layer to form a common molten pool, and the welding wire is heated and melted by the multiple plasma arcs at a position above the common molten pool to form a layer of deposition layer on the surface of the substrate or the deposited layer; S5: when a layer of deposition layer is completed, the motion device drives the additive manufacturing-based welding gun device to rise according to the thickness of the layer of deposition layer, and then step S4 is performed to perform fused deposition of another layer of deposition layer; S6: repeat step S5 until the workpiece corresponding to the three-dimensional model is formed by additive manufacturing.

[0016] The fuse additive manufacturing method according to the third aspect of the present application has at least the following beneficial effects: before starting the fuse deposition work, the three-dimensional modeling work needs to be completed first, and then the three-dimensional model is processed to obtain the deposition track of each layer; during the fuse deposition work, the additive manufacturing-based welding gun device moves along the deposition track under the driving action of the motion device, and at the same time, the wire feeding mechanism continuously feeds the welding wire, so that the welding wire can pass through the wire feeding channel, the feeding channel and the compression nozzle in turn from top to bottom, the gun head generates multiple plasma arcs, which can not only preheat the non-melted welding wire passing through the compression nozzle, but also melt the welding wire passing through the compression nozzle, so that the welding wire can form a deposition layer on the surface of the substrate or the deposited layer, thereby improving the deposition efficiency; and since the welding wire remains perpendicular to the substrate or the deposited layer during the additive manufacturing process, the multiple plasma arcs are uniformly arranged along the circumference of the welding wire, so that the directional influence between the heat source and the welding wire during the additive manufacturing process can be reduced, and the problem of shape limitation of the molded part caused by the use of the off-axis wire feeding method in the prior art can be avoided. When each layer of deposition layer is completed, the additive manufacturing-based welding gun device is driven by the motion device to rise by a certain height distance, and then the processing work of another layer of deposition layer is started, until the workpiece is obtained by the additive manufacturing method.

[0017] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by means of the instrumentalities particularly pointed out in the description and claims, and the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the additive manufacturing-based welding gun device according to the embodiment of the present application; Figure 2 is a schematic diagram of the arrangement of the four tungsten electrodes with respect to the welding wire in the additive manufacturing-based welding gun device according to the embodiment of the present application; Figure 3 is a flowchart of the fuse additive manufacturing method according to the embodiment of the present application.

[0019] Reference signs: 110, welding wire; 111, molten droplet; 112, common molten pool; 120, substrate; 130, deposited layer; 210, wire feeding pipe; 220, wire feeding wheel; 230, inner shell; 240, tungsten electrode; 241, plasma arc; 250, outer shell; 260, gas flow channel; 270, water cooling channel; 280, compression nozzle. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described below in the detailed description and illustrated in the accompanying drawings by using examples, which are exemplary only and not intended to limit the present application, with like or similar elements denoted throughout by like reference numerals.

[0021] In the description of the present application, it should be understood that the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0022] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "connected", "connected" 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, or it can be connected inside 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.

[0023] The following description is made with reference to the drawings Figures 1 to 3 A welding gun device based on additive manufacturing, a fused filament additive manufacturing system and a method according to embodiments of the present application are described.

[0024] As shown in Figure 1 and Figure 2 The welding gun device based on additive manufacturing according to the first embodiment of the present application can be applied to the fused filament additive manufacturing work, and the welding gun device based on additive manufacturing of the present embodiment can reduce the directional influence between the heat source and the wire (or welding wire 110) in the additive manufacturing process, reduce the limitation of the shape of the molded part, and improve the fused filament deposition efficiency, thereby improving the fused filament additive manufacturing situation.

[0025] As shown in Figure 1 and Figure 2 The welding gun device based on additive manufacturing includes a wire feeding mechanism and a gun head.

[0026] The wire feeding mechanism is provided with a wire feeding channel, which extends through the wire feeding channel in the up-down direction. The wire feeding channel is used for the welding wire 110 to move from top to bottom. It can be understood that the wire feeding channel can be circular or square in the up-down direction, which can allow the welding wire 110 to pass downward. The wire feeding mechanism can apply a conveying action to the welding wire 110, so that the welding wire 110 passes through the wire feeding channel in a vertical state to realize the continuous wire feeding function. The center axis of the welding wire 110 and the center axis of the wire feeding channel coincide with each other and extend in the up-down direction.

[0027] The gun head comprises a shell, tungsten electrodes 240 and a compression nozzle 280. The shell is connected to the wire feeding mechanism, for example, by screwing. The shell has a cavity and a feeding channel extending vertically therethrough and communicating with the cavity. The feeding channel, the wire feeding channel and the compression nozzle 280 are coaxially arranged, with the feeding channel below the wire feeding channel, the upper end of the feeding channel communicating with the lower end of the wire feeding channel, and the compression nozzle 280 arranged at the lower end of the feeding channel and fixed to the shell, so that the compression nozzle 280 can communicate with the wire feeding channel, and the welding wire 110 can move down along the wire feeding channel, the feeding channel and the compression nozzle 280 in turn.

[0028] In this embodiment, as shown in Figure 1 The shell comprises an inner shell 230 and an outer shell 250, which are fixedly connected to form the cavity and the feeding channel. The inner shell 230 is arranged closer to the wire feeding mechanism than the outer shell 250. The wire feeding mechanism is arranged outside the cavity of the shell. Of course, it is not excluded that the wire feeding mechanism is arranged inside the shell.

[0029] The tungsten electrodes 240 are arranged in the cavity of the shell. There are at least two tungsten electrodes 240, which are uniformly arranged along the circumference of the feeding channel. In some examples, there are two tungsten electrodes 240, which are arranged on the left and right sides of the feeding channel in the horizontal direction, for example, the left and right directions. In other examples, there are three tungsten electrodes 240, which are uniformly arranged at an angle of 120°.

[0030] In this embodiment, as shown in Figure 1 and Figure 2 There are four tungsten electrodes 240, which are uniformly arranged along the circumference of the feeding channel. Therefore, the four tungsten electrodes 240 can be arranged in a circle around the welding wire 110 in the feeding channel. Specifically, two tungsten electrodes 240 are arranged on the front and back sides of the welding wire 110, and the plasma arcs 241 formed by the two tungsten electrodes 240 are symmetrically arranged on the front and back sides of the welding wire 110. The other two tungsten electrodes 240 are arranged on the left and right sides of the welding wire 110, and the plasma arcs 241 formed by the two tungsten electrodes 240 are symmetrically arranged on the left and right sides of the welding wire 110. By integrating multiple tungsten electrodes 240 in the same shell, the welding gun device based on additive manufacturing becomes more compact.

[0031] All the tungsten electrodes 240 are configured to generate plasma arcs 241 in cooperation with the compression nozzle 280 when energized, and the plasma arcs 241 can be output together with the welding wire 110 from the same compression nozzle 280. In this embodiment, as shown in Figure 1As shown, the tungsten electrode 240 is arranged in an inclined manner, specifically, the tungsten electrode 240 is inclined downward from top to bottom to the feeding passage, and the tip of the tungsten electrode 240 is located in the compression nozzle 280. The tungsten electrode 240 is provided with an electrically connected end, so that the tip of the tungsten electrode 240 can emit electrons under the condition of being electrified. The central axis of the tungsten electrode 240 forms an angle a with the horizontal plane, and the angle a is less than 90°, and the value of the angle a can be 30° to 70°.

[0032] It can be understood that the specific shape of the shell and the cavity is not limited and can be designed according to actual needs. The number of tungsten electrodes 240 can be selected according to actual design conditions. The tungsten electrode 240 as an electron emission source can discharge, and by applying a certain voltage between the tungsten electrode 240 as a cathode and the compression nozzle 280 as an anode, triggering gas ionization through high-frequency oscillation or high-voltage pulse, forming a free arc, the free arc will be subjected to mechanical compression effect when passing through the compression nozzle 280, prompting the arc column cross section to be reduced to millimeter level, the energy density is greatly improved, and finally the free arc is compressed into a high-energy-density plasma arc 241. Each tungsten electrode 240 can form and maintain a plasma arc 241 under the cooperation of the compression nozzle 280, prompting the gun head to be able to generate multiple plasma arcs 241. Since the principle of generating the plasma arc 241 is the prior art, those skilled in the art should clearly understand that it is not repeated here.

[0033] The wire feeding mechanism can transport the long welding wire 110 when in operation, so that the welding wire 110 can pass through the wire feeding passage and the feeding passage in turn and be output from the compression nozzle 280. The gun head can generate multiple plasma arcs 241 when in operation, so that the multiple plasma arcs 241 can be output outward through the compression nozzle 280, and the multiple plasma arcs 241 can act on the part of the welding wire 110 passing through the compression nozzle 280. The gun head is configured to preheat the part of the welding wire 110 located in the compression nozzle 280 when generating the plasma arc 241, so that the temperature of the part of the welding wire 110 rises, and the part of the welding wire 110 located below the compression nozzle 280 is heated and melted, so that the part of the welding wire 110 can quickly become a droplet 111, so that the droplet 111 can form a deposited layer on the substrate 120 or the deposited layer 130.

[0034] In some embodiments, as Figure 1As shown, the structure of the wire feeding mechanism includes a wire feeding tube 210 and at least one pair of wire feeding wheels 220. The wire feeding tube 210 is provided with a wire feeding passage extending through in the up-down direction, and the at least one pair of wire feeding wheels 220 can be arranged in the wire feeding passage, or above or below the wire feeding passage. The at least one pair of wire feeding wheels 220 are configured to feed the welding wire 110 during rotation, so that the welding wire 110 can pass through the wire feeding passage and the feeding passage in sequence, and extend downward from the compression nozzle 280. For example, the at least one pair of wire feeding wheels 220 are arranged above the wire feeding passage, and the at least one pair of wire feeding wheels 220 are formed with a feeding passage coaxially arranged with and communicating with the wire feeding passage.

[0035] It can be understood that each pair of wire feeding wheels 220 includes two wire feeding wheels 220 arranged in a spaced manner in the horizontal direction, such as the left-right direction, so that a feeding passage is formed between the two wire feeding wheels 220, and the central axis of the wire feeding wheel 220 is perpendicular to the up-down direction. When the welding wire 110 enters the feeding passage, the welding wire 110 can move downward along the feeding passage under the rotation of the two wire feeding wheels 220, and enter the wire feeding passage. The two wire feeding wheels 220 can be rotated by the rotation of a rotation driving device. The rotation driving device can include a motor and a transmission structure, such as a gear transmission structure. The motor drives the two wire feeding wheels 220 to rotate in opposite directions through the gear transmission structure.

[0036] In the embodiment, the wire feeding wheels 220 are arranged in only one pair. Of course, it is not excluded that in other embodiments, the wire feeding wheels 220 are arranged in multiple pairs and arranged at a set interval in the up-down direction.

[0037] In some embodiments, as shown, Figure 1 The compression nozzle 280 is provided with a water cooling passage 270, a water inlet and a water outlet, wherein the water inlet and the water outlet are in communication with the water cooling passage 270, and the water cooling passage 270 extends along the circumference of the feeding passage. The water cooling passage 270 circulates cooling water.

[0038] It can be understood that the water cooling channel 270 can be annular, and the water inlet and the water outlet are respectively located on opposite sides of the water cooling channel 270, such as the front and rear sides. The water inlet and the water outlet can be respectively connected with an external cooling water circulation system, so that the cooling water can flow into the water cooling channel 270 through the water inlet and flow out from the water outlet. The cooling water can cool the compression nozzle 280 and take away the heat of the compression nozzle 280, so as to avoid the phenomenon that the compression nozzle 280 is softened or deformed due to overheating, or even burned through by the plasma arc 241. Moreover, the cooling water forms a cold gas film near the inner wall of the compression nozzle 280, further reduces the effective conduction area of the arc column, and thus further improves the energy density and temperature of the arc column; at the same time, the temperature of the compression nozzle 280 is stable, which helps to maintain the stability of the surrounding gas flow field, helps to stabilize the arc, and prevents the occurrence of arc drift or double arc phenomenon.

[0039] In some embodiments, as shown in FIG. 2, the shell is provided with a gas flow channel 260, a gas inlet and a gas outlet, wherein the gas inlet and the gas outlet are both in communication with the gas flow channel 260, the gas flow channel 260 is inclined from top to bottom to the feeding channel, the gas inlet is located above the gas outlet, the gas inlet can be connected with an external argon injection device, so that argon can flow into the gas flow channel 260 through the gas inlet, and the gas outlet is in communication with the feeding channel. The outer periphery of each tungsten electrode 240 is provided with a plurality of gas flow channels 260, and the plurality of gas flow channels 260 are configured to allow argon to flow through and form a protective layer for protecting the tungsten electrode 240. Figure 1 In some embodiments, as shown in FIG. 2, the shell is provided with a gas flow channel 260, a gas inlet and a gas outlet, wherein the gas inlet and the gas outlet are both in communication with the gas flow channel 260, the gas flow channel 260 is inclined from top to bottom to the feeding channel, the gas inlet is located above the gas outlet, the gas inlet can be connected with an external argon injection device, so that argon can flow into the gas flow channel 260 through the gas inlet, and the gas outlet is in communication with the feeding channel. The outer periphery of each tungsten electrode 240 is provided with a plurality of gas flow channels 260, and the plurality of gas flow channels 260 are configured to allow argon to flow through and form a protective layer for protecting the tungsten electrode 240.

[0040] Figure 1 In some embodiments, as shown in FIG. 2, the shell is provided with a gas flow channel 260, a gas inlet and a gas outlet, wherein the gas inlet and the gas outlet are both in communication with the gas flow channel 260, the gas flow channel 260 is inclined from top to bottom to the feeding channel, the gas inlet is located above the gas outlet, the gas inlet can be connected with an external argon injection device, so that argon can flow into the gas flow channel 260 through the gas inlet, and the gas outlet is in communication with the feeding channel. The outer periphery of each tungsten electrode 240 is provided with a plurality of gas flow channels 260, and the plurality of gas flow channels 260 are configured to allow argon to flow through and form a protective layer for protecting the tungsten electrode 240.

[0041] It can be understood that since the tungsten electrode 240 will reach a high temperature state under the arc, if the tungsten electrode 240 is directly exposed to air, the tungsten in the tungsten electrode 240 will rapidly react with oxygen to generate tungsten oxide and ablate and consume, thereby shortening the service life of the tungsten electrode 240. Therefore, by arranging the gas flow channel 260 on the outer periphery of the tungsten electrode 240, the argon in the gas flow channel 260 directly contacts the tungsten electrode 240 during flow and forms an inert protective layer to isolate the tungsten electrode 240 from the surrounding air, so as to ensure that the tungsten electrode 240 can still work stably at high temperature. Moreover, the argon flowing out of the gas outlet flows to the compression nozzle 280 through the feeding channel and flows out of the compression nozzle 280, so that the continuously flowing argon not only protects the tungsten electrode 240, but also takes away part of the heat from the tungsten electrode 240 and the compression nozzle 280, thereby achieving a certain cooling effect.

[0042] ​In addition, since argon is a single-atom inert gas, its ionization energy is relatively low, and its thermal conductivity is low, so argon is more easily broken down and ionized into conductive plasma, making the arc striking process easier and more reliable, and argon can also play a role in stabilizing the arc, so that the arc column can remain relatively concentrated and stable and will not drift randomly.

[0043] In the use process of the welding torch device based on additive manufacturing provided in the first aspect of the present application, when the wire feeding mechanism is in operation, the welding wire 110 moves from top to bottom and passes through the wire feeding channel, the feeding channel and the compression nozzle 280 in turn. At this time, the torch head can use multiple energized tungsten electrodes 240 in cooperation with the compression nozzle 280 to generate multiple plasma arcs 241. The multiple plasma arcs and the welding wire 110 can pass through the same compression nozzle 280 and be output outward. Since the multiple plasma arcs 241 can form a preheating field in the compression nozzle 280, when the welding wire 110 moves downward along the feeding channel and the compression nozzle 280, the welding wire 110 will enter the preheating field, so that the multiple plasma arcs 241 can preheat the welding wire 110 before melting, thereby accelerating the melting speed of the welding wire 110 and effectively improving the deposition efficiency.

[0044] It can be understood that in the additive manufacturing process, the multiple plasma arcs 241 are output from the compression nozzle 280 and act on the surface of the substrate 120 or the surface of the deposited layer 130 to process a common molten pool 112. At the same time, the welding wire 110 is continuously heated by the multiple plasma arcs 241 before melting during the process of passing through the compression nozzle 280, so that the welding wire 110 output from the compression nozzle 280 can be sent to a position above the common molten pool 112 and rapidly melted above the common molten pool 112 to form a droplet 111. Since the welding wire 110 is melted above the common molten pool 112 during continuous wire feeding, the welding wire 110 can form a deposited layer on the surface of the substrate 120 or the deposited layer 130. By such design, the preheating effect of the welding wire 110 by the multiple plasma arcs 241 in the compression nozzle 280 before entering the common molten pool 112 can promote the improvement of the wire melting deposition efficiency.

[0045] Since the multiple plasma arcs 241 output from the compression nozzle 280 can form a composite plasma arc 241 beam and are arranged in a circle with the axis of the welding wire 110 (i.e. the axis of the feeding channel and the wire feeding channel) as the array center, and the welding wire 110 remains vertical during the additive manufacturing process, the influence of the inconsistency between the direction of the heat source and the feeding direction of the welding wire 110 can be reduced, effectively reducing the limitation on the shape of the formed part.

[0046] As Figure 1 and Figure 2As shown, the fused wire additive manufacturing system according to a second aspect embodiment of the present invention includes a motion device and an additive manufacturing-based welding torch device as described in the first aspect embodiment. The movable end of the motion device is fixedly connected to a housing, and the motion device is configured to drive the additive manufacturing-based welding torch device to move along a deposition trajectory, thereby enabling the additive manufacturing-based welding torch device to perform fused wire deposition.

[0047] Understandably, the motion device is a multi-axis robotic arm or a multi-axis linear module. In additive manufacturing, the first step is to create a 3D model of the part. The resulting 3D model is then layered to plan the deposition path, thus obtaining the corresponding printing data file. This printing data file is then imported into the control system of the fused wire additive manufacturing system. The control system controls the motion device and the additive manufacturing-based welding torch according to the printing data file, allowing the welding torch to perform layer-by-layer fused wire deposition under the action of the motion device, ultimately forming a 3D part.

[0048] As the welding torch device driven by the motion device moves along the deposition trajectory to perform wire deposition, the multiple plasma arcs 241 generated by the torch head can preheat the welding wire 110 within the compression nozzle 280. The multiple plasma arcs 241 are evenly distributed around the vertically descending welding wire 110, which promotes faster melting of the welding wire 110, thus improving deposition efficiency. Furthermore, it can reduce the directional influence between the heat source and the welding wire 110 during additive manufacturing, reduce the limiting effect on the shape of the formed part, and help improve the quality of additive manufacturing.

[0049] like Figures 1 to 3 As shown, the fused wire additive manufacturing method according to a third aspect embodiment of the present invention, applied to a fused wire additive manufacturing system as described in the second aspect embodiment, includes the following steps: S1: Perform 3D modeling on the target workpiece and generate a 3D model corresponding to the additively formed part.

[0050] S2: The 3D model is layered and additive path planning is performed on each layer to generate deposition trajectories.

[0051] S3: Place the pre-treated substrate 120 on the worktable.

[0052] S4: The additive manufacturing based welding torch device is driven by the motion device to move along the deposition trajectory, the wire feeding mechanism and the torch head are operated, the multi-beam plasma arc 241 and the preheated welding wire 110 are output from the compression nozzle 280, the multi-beam plasma arc 241 acts on the surface of the substrate 120 or the deposited layer 130 to form a common molten pool 112, and the welding wire 110 is heated and melted by the multi-beam plasma arc at a position above the common molten pool 112, and a layer of deposited layer is formed on the surface of the substrate 120 or the deposited layer 130.

[0053] S5: When a layer of deposited layer is completed, the additive manufacturing based welding torch device is driven by the motion device to rise according to the thickness of the layer of deposited layer, and then another layer of deposited layer is fused and deposited according to step S4.

[0054] S6: Repeat step S5 until the workpiece corresponding to the three-dimensional model is additively manufactured.

[0055] It can be understood that in step S1, since the three-dimensional modeling work is completed before starting the fused filament deposition work, the existing three-dimensional modeling software can be used to model the target workpiece to obtain a three-dimensional model. In step S2, after obtaining the three-dimensional model file, the imported three-dimensional model file can be read by using the existing slicing software, and after setting the process parameters, the slicing software automatically layers and plans the path to generate the deposition trajectory, and finally obtains a data file containing all motion and control instructions, such as a G-code file required by the fused filament additive manufacturing system. The three-dimensional model is layered to obtain the deposition trajectory of each layer. In step S3, the pretreatment of the substrate 120 usually includes physical cleaning and leveling, surface treatment, etc. Those skilled in the art should clearly understand that steps S1, S2 and S3 can be completed by existing technical means, and will not be described here.

[0056] In step S4, during the fused filament deposition work, the additive manufacturing based welding torch device moves along the deposition trajectory under the driving action of the motion device, and the wire feeding mechanism operates, the welding wire 110 is continuously fed to the wire feeding channel under the driving action of the wire feeding wheel 220, so that the welding wire 110 can pass through the wire feeding channel, the feeding channel and the compression nozzle 280 in turn from top to bottom, and the torch head also operates when the plasma power source of the torch head is started. All tungsten electrodes 240 can generate multi-beam plasma arc 241 under the cooperation of the compression nozzle 280, the multi-beam plasma arc 241 is output from the compression nozzle 280, and can act on the surface of the substrate 120 or the deposited layer 130 to form a common molten pool 112.

[0057] In addition, the multi-beam plasma arc 241 not only can preheat the non-melted welding wire 110 passing through the compression nozzle 280, but also can heat and melt the welding wire 110 passing through the compression nozzle 280, so that the preheated welding wire 110 can be sent to the upper side of the co-melt pool 112 after passing through the compression nozzle 280 and be melted in the process of continuous wire feeding, so as to form a deposited layer on the surface of the substrate 120 or the surface of the deposited layer 130, thereby improving the cladding efficiency. Moreover, since the welding wire 110 remains perpendicular to the substrate 120 or the deposited layer 130 in the additive manufacturing process, the multi-beam plasma arc 241 is uniformly arranged along the circumference of the welding wire 110, so that the directional influence between the heat source and the welding wire 110 in the additive manufacturing process can be reduced, and the problem that the shape of the formed part is limited due to the use of the off-axis wire feeding mode in the prior art can be effectively avoided.

[0058] In steps S5 and S6, after each layer of the deposited layer is completed, the welding gun device based on additive manufacturing is driven by the movement device to rise by a certain height distance, and then the processing work of another layer of the deposited layer is started, until the workpiece is obtained by the additive manufacturing method.

[0059] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0060] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A welding torch device based on additive manufacturing, characterized in that, include: The wire feeding mechanism is provided with a wire feeding channel for the welding wire to move from top to bottom; The gun head includes a housing, a tungsten electrode, and a compression nozzle. The housing is connected to the wire feeding mechanism. The housing has a cavity and a feeding channel. The feeding channel extends vertically and communicates with the cavity. The feeding channel, the wire feeding channel, and the compression nozzle are coaxially arranged. The upper opening of the feeding channel communicates with the lower opening of the wire feeding channel. The compression nozzle is located at the lower opening of the feeding channel and is connected to the housing. The tungsten electrode is located in the cavity. There are at least two tungsten electrodes, which are evenly arranged circumferentially along the circumference of the feeding channel. All the tungsten electrodes are configured to cooperate with the compression nozzle to generate a plasma arc when energized. The gun head is configured to preheat the portion of the welding wire located inside the compression nozzle when a plasma arc is generated, and to heat and melt the portion of the welding wire located below the compression nozzle.

2. The welding torch device based on additive manufacturing according to claim 1, characterized in that, The tungsten electrode is provided in four parts and is evenly arranged in a circle along the circumference of the feeding channel.

3. The additive manufacturing-based welding torch device according to claim 1 or 2, characterized in that, The tungsten electrode is inclined downwards toward the feeding channel, and the tip of the tungsten electrode is located inside the compression nozzle.

4. The additive manufacturing-based welding torch device according to claim 3, characterized in that, The housing is provided with a gas flow channel and an inlet and an outlet that are both connected to the gas flow channel. The gas flow channel is inclined from top to bottom toward the feeding channel. The outlet is connected to the feeding channel. Each tungsten electrode has a plurality of gas flow channels on its outer periphery. The plurality of gas flow channels are configured to allow argon gas to flow and form a protective layer for protecting the tungsten electrode.

5. The welding torch device based on additive manufacturing according to claim 1, characterized in that, The wire feeding mechanism includes a wire feeding tube and at least one pair of wire feeding wheels. The wire feeding tube is provided with a wire feeding channel extending through it in a vertical direction. The at least one pair of wire feeding wheels are configured to feed the welding wire during rotation, so that the welding wire passes through the wire feeding channel and the feeding channel in sequence and extends downward from the compression nozzle.

6. The additive manufacturing-based welding torch device according to claim 5, characterized in that, At least one pair of the wire feeding wheels are disposed above the wire feeding channel, and at least one pair of the wire feeding wheels form a conveying channel, which is coaxially arranged and connected to the wire feeding channel.

7. The welding torch device based on additive manufacturing according to claim 1, characterized in that, The compression nozzle is provided with a water cooling channel and an inlet and an outlet that are both connected to the water cooling channel. The water cooling channel extends circumferentially along the feeding channel.

8. A fused wire additive manufacturing system, characterized in that, include: The additive manufacturing-based welding torch apparatus as described in any one of claims 1 to 7; A motion device, the movable end of which is connected to the housing, is configured to drive the additive manufacturing-based welding torch device to move along a deposition trajectory so that the additive manufacturing-based welding torch device can perform molten wire deposition.

9. The fused wire additive manufacturing system according to claim 8, characterized in that, The motion device is a multi-axis manipulator or a multi-axis linear module.

10. A fused wire additive manufacturing method, characterized in that, Applied to the fused wire additive manufacturing system as described in claim 8 or 9, the fused wire additive manufacturing method includes the following steps: S1: Perform 3D modeling on the target workpiece and generate a 3D model corresponding to the additively formed part; S2: The three-dimensional model is layered, and additive path planning is performed on each layer to generate a deposition trajectory; S3: Place the pre-treated substrate on the worktable; S4: The motion device drives the additive manufacturing-based welding torch device to move along the deposition trajectory. The wire feeding mechanism and the torch head operate, so that multiple plasma arcs and preheated welding wire are output from the compression nozzle. The multiple plasma arcs act on the surface of the substrate or the deposited layer to form a eutectic pool. At the same time, the welding wire is heated and melted by the multiple plasma arcs above the eutectic pool, and a deposition layer is formed on the surface of the substrate or the deposited layer. S5: After one layer of deposition is completed, the welding gun device based on additive manufacturing is driven to rise according to the thickness of one layer of deposition through the motion device, and then another layer of deposition is melted and deposited according to step S4. S6: Repeat step S5 until an additive manufacturing process is completed to produce a workpiece corresponding to the three-dimensional model.

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