Four-tungsten-electrode rotary additive manufacturing device and additive manufacturing method

Abstract

The invention relates to the technical field of argon tungsten-arc welding additive manufacturing, and provides a four-tungsten-electrode rotating additive manufacturing device and an additive manufacturing method.The device comprises a base, a rotating disc, a wire feeding gun and four TIG welding torches, the rotating disc is rotatably installed on the base, the wire feeding gun penetrates through the center of the rotating disc to be fixedly installed on the base, and the rotating disc can rotate around the wire feeding gun; the four TIG welding guns are evenly distributed on the rotary disc around the wire feeding gun, the four TIG welding guns are symmetrically arranged with the wire feeding gun as the center, and tungsten electrodes of the four TIG welding guns face welding wires sent out by the wire feeding gun; the rotating disc drives the four TIG welding guns to rotate, and rotating electric arcs are formed during welding. According to the method, the size of molten drops can be accurately controlled, meanwhile, molten drop transition is promoted with higher energy density, and the additive shape control effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tungsten electrode argon arc welding additive manufacturing, and in particular to a four-tungsten electrode rotating additive manufacturing device and an additive manufacturing method. Background Art

[0002] Arc fuse additive manufacturing technology typically uses an arc as a heat source to melt metal wire, programs the movement paths of the wire feed end and the workpiece end, and uses flat welding to print complex metal parts without support as the wire feed end moves or the workpiece end moves. However, the additive process is often accompanied by local dimensional deviations due to dimensional unevenness during droplet transition. Therefore, if additive manufacturing can be performed in a transition method that controls the size of the droplet, the accuracy and efficiency of the additive parts can be improved.

[0003] During flat welding, surface tension acts as a barrier to droplet transfer, spherically shaping the droplet and causing physical adsorption, which causes the droplet to suspend at the solid-liquid interface. In conventional additive manufacturing, the introduction of a transverse magnetic field, coupled with the flow of current through the molten pool, stirs the molten pool, enhancing its fluidity, helping to eliminate pores, refine grains, and ultimately improve the quality of the additively manufactured part. However, the directional relationship between the transverse magnetic field and the current produces an uneven component of force in the horizontal direction, causing deviation in the droplet transfer. For example, when using a DC positive connection with a transverse magnetic field, a droplet is formed on one side after the welding wire is extended into the arc. The droplet acts as a liquid conductor in the arc. At this time, the current flowing through the liquid conductor points from the workpiece to the tungsten electrode, with an upward and slightly forward direction. Under the action of the magnetic field force, according to the left-hand rule, the direction of the magnetic field force, the direction of the current and the direction of the force are orthogonal to each other. At this time, the magnetic field force on the droplet points to the lower front position, and the horizontal component of the magnetic field force is significantly stronger than the vertical component. The horizontal component will not promote the droplet transfer, and will have the side effect of causing the droplet to deviate from the falling axis during transfer. Therefore, this method is not effective in controlling the droplet transfer. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a four-tungsten pole rotating additive manufacturing device and a method of use, which can accurately control the size of the molten droplet, while promoting the molten droplet transition with a higher energy density, thereby improving the additive shape control effect.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A four-tungsten electrode rotary additive manufacturing device, characterized by comprising a base, a turntable, a wire feed gun, four TIG welding guns, a circuit system, a motor, and a transmission gear set, wherein the motor is fixed to the base, and the output shaft of the motor is connected to the turntable via the transmission gear set, the turntable is rotatably mounted on the base, the wire feed gun is fixedly mounted on the base through the center of the turntable, and the turntable is rotatable around the wire feed gun;

[0007] Four TIG welding guns are evenly distributed around the wire feeding gun on the turntable, and the four TIG welding guns are symmetrically arranged with the wire feeding gun as the center, and the tungsten electrodes of the four TIG welding guns are facing the welding wire fed by the wire feeding gun; the four TIG welding guns and the wire feeding gun are electrically connected to the power supply through a circuit system that penetrates the base and the turntable.

[0008] Furthermore, the turntable and the base are rotatably connected via a second bearing, and the wire feeding gun and the turntable are rotatably connected via a first bearing; the gear set includes a driven gear fixedly connected to the turntable and a driving gear fixedly connected to the output shaft, and the driven gear is in meshing engagement with the driving gear.

[0009] Furthermore, the circuit system includes a conductive pile that can rotate with the turntable, and four annular conductive rails are arranged around the outer circumference of the conductive pile. Wires are provided inside the pile, each connected to one of the four annular conductive rails and connected to four TIG welding guns respectively; the four annular conductive rails are respectively in contact with a brush and are electrically connected to the power supply through a wire running through the base.

[0010] Furthermore, the four TIG welding guns are opposite to each other in pairs, and the connection line between the tungsten electrodes of the two oppositely arranged TIG welding guns in each group passes through the front end of the welding wire; the four TIG welding guns are respectively inclined toward the wire feeding gun, and the connection between the four TIG welding guns and the turntable is detachable, and the distance between the wire feeding guns is adjustable.

[0011] Furthermore, the TIG welding gun includes a gun body and a tungsten electrode assembly arranged on the gun body, the tungsten electrode assembly includes a welding gun tube, a tungsten electrode clamp, a tungsten electrode, and a ceramic nozzle, the welding gun tube and the ceramic nozzle are connected by threads, the tungsten electrode clamp is installed inside the welding gun tube and is axially fixed by the ceramic nozzle, and the tungsten electrode is installed inside the tungsten electrode clamp and locked by a conical surface.

[0012] Furthermore, the tip of the tungsten electrode is bent inward and faces the wire feeding gun.

[0013] Furthermore, the wire feeding gun includes a gas protection mechanism and a cooling mechanism. The gas protection mechanism is located between the wire feeding nozzle and the wire feeding tube of the wire feeding gun, and the cooling mechanism is located between the TIG welding gun and the wire feeding gun.

[0014] Furthermore, the four tungsten electrodes are powered by two DC pulse power supplies, a group of two TIG welding guns arranged opposite to each other are respectively connected to the positive and negative poles of one power supply, and another group of two TIG welding guns arranged opposite to each other are respectively connected to the positive and negative poles of another power supply.

[0015] Furthermore, the four tungsten electrodes are powered by a power supply, the four TIG welding guns are connected to the positive pole of the same power supply, and the welding wires are connected to the negative pole of the power supply.

[0016] The additive manufacturing method of the four-tungsten-pole rotating additive manufacturing device is characterized by comprising the following steps:

[0017] Adjust the position of the wire feed gun and TIG welding gun to focus on the front end of the welding wire and plan the additive manufacturing path;

[0018] In dual power mode, the gas, liquid, and electric switches are turned on to start the additive manufacturing process. One set of TIG welding guns is connected to the positive and negative terminals of one power source, while the other set of TIG welding guns is connected to the positive and negative terminals of the other power source. Two transverse pulse arcs are formed during the additive manufacturing process. The turntable drives the four TIG welding guns to rotate around the wire feed gun, forming a rotating arc during welding. The welding wire is melted as it passes through the rotating arc. At the same time, the cutting process during the rotating arc and the combined effects of gravity turn the molten droplets into controllable droplets that drip downward.

[0019] In single power mode, the additive manufacturing process begins by turning on the gas, hydraulic, and electrical switches. Four TIG welding guns are connected to the positive terminal, and the welding wire is connected to the negative terminal. This creates four transverse pulsed arcs during the additive manufacturing process. A turntable drives the four TIG welding guns to rotate around the wire feed gun, forming a rotating arc during welding. The welding wire melts as it passes through the rotating arc, and the combined effects of the arc's cutting action and gravity transform the wire into molten droplets of controlled size that drip downward.

[0020] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0021] The four-tungsten electrode rotary additive manufacturing device provided by the present invention includes a base, a turntable, a wire feeding gun, and four TIG welding guns. The base is used to install the turntable, and the wire feeding gun is installed in the center of the turntable. TIG welding guns are respectively installed at four directions of the wire feeding gun. The relatively arranged TIG welding guns are divided into a group, which are respectively inclined toward the wire feeding guns and symmetrically distributed. The straight lines where the tungsten electrodes of the two groups of TIG welding guns are located intersect at the front end of the welding wire. The wire feeding gun is fixed to the base and is not affected by the rotation of the turntable. The turntable can drive the TIG welding gun to rotate and then form a rotating arc during welding, which can overcome the adsorption effect of the welding wire on the molten droplet. The lateral force of the molten droplet is changed by the rotating arc, and it is selectively cut by the size of the rotation speed during its growth, thereby realizing precise control of the molten droplet size.

[0022] The present invention uses the rotating arc generated between the tungsten electrodes of the rotating TIG welding gun as the heat source to melt the welding wire, does not form a current loop with the welding workpiece, does not form a molten pool, and avoids the molten pool affecting the molten droplet transfer. Since the force of the rotating arc on the molten droplet is located in the horizontal plane and is evenly distributed around the molten droplet, a transverse cutting effect is formed, and then combined with gravity, the molten droplet can be selected to drip at a certain moment of growth according to the control of the rotation speed, the molten droplet transfer is stable, and the additive shape control effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of the four-tungsten-pole rotary additive manufacturing device of the present invention;

[0024] Figure 2 Schematic diagram of the cross-sectional structure of the four-tungsten-pole rotary additive manufacturing device of the present invention;

[0025] Figure 3 Schematic diagram of the power transmission structure of the turntable;

[0026] Figure 4 Schematic diagram of the circuit system structure of four TIG welding guns.

[0027] Description of reference numerals:

[0028] 1. First TIG welding gun, 2. Second TIG welding gun, 3. Wire feed gun, 4. Turntable, 5. Base, 6. Third TIG welding gun, 7. Fourth TIG welding gun, 8. First bearing, 9. Second bearing, 10. Driven gear, 11. Driving gear, 12. Output shaft, 13. Motor, 14. Conductive pile, 15. First annular conductive rail, 16. Second annular conductive rail, 17. Third annular conductive rail, 18. Fourth annular conductive rail, 19. First brush, 20. Second brush, 21. Third brush, 22. Fourth brush, 23. Tungsten electrode. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] The four-tungsten-electrode rotary additive manufacturing device described in the present invention drives four TIG welding guns to rotate through a turntable, forming a rotating arc during welding, accurately controlling the size of the molten droplet, and promoting the molten droplet transfer with a higher energy density, thereby improving the additive shape control effect.

[0031] Example 1

[0032] like Figure 1As shown, the four-tungsten electrode rotary additive manufacturing device includes a base 5, a turntable 4, a wire feeder 3, and a first TIG welding gun 1, a second TIG welding gun 2, a third TIG welding gun 6, and a fourth TIG welding gun 7 distributed around the wire feeder 3. The turntable 4 is rotatably mounted on the base 5, and the wire feeder 3 is fixedly mounted on the base 5 through the center of the turntable 4. The turntable 4 can rotate around the wire feeder 3; the wire feeder is fixed to the base and is not affected by the rotation of the turntable.

[0033] The first TIG welding gun 1, the second TIG welding gun 2, the third TIG welding gun 6, and the fourth TIG welding gun 7 are evenly arranged on the turntable 4 around the wire feeding gun 3. The first TIG welding gun 1, the second TIG welding gun 2, the third TIG welding gun 6, and the fourth TIG welding gun 7 are symmetrically arranged with the wire feeding gun 3 as the center. The tungsten electrodes 23 of the four TIG welding guns face the welding wire fed by the wire feeding gun 3. The turntable 4 drives the four TIG welding guns to rotate, forming a rotating arc during welding. This rotating arc has a higher energy density due to the double arc cross rotation. Therefore, it can melt the welding wire with a higher melting point to form a molten droplet. The rotating arc can form a transverse cutting effect on the molten droplet. Then, the size of the molten droplet can be more accurately controlled by controlling the rotation speed to achieve a better additive control effect.

[0034] Specifically, if Figure 2 As shown, in the embodiment of the present invention, the plane where the base 5 is located is the xy plane, where the east-west direction corresponds to the y-axis direction, and the north-south direction corresponds to the x-axis direction. The first TIG welding gun 1, the second TIG welding gun 2, the third TIG welding gun 6, and the fourth TIG welding gun 7 are respectively arranged in the east, west, south, and north directions of the wire feeder gun. The first TIG welding gun 1 and the fourth TIG welding gun 7 arranged opposite to each other in the east-west direction form a group, and the second TIG welding gun 2 and the third TIG welding gun 6 arranged opposite to each other in the north-south direction form a group. They are respectively arranged obliquely toward the wire feeder gun 3, and the straight lines on which the tungsten electrodes of the two groups of TIG welding guns are located intersect at the front end of the welding wire.

[0035] The lower portion of the turntable 4 is a circular disc, with an outer gear on its central outer surface. The outer circumference of the upper portion is provided with a first annular conductive track 15, a second annular conductive track 16, a third annular conductive track 17, and a fourth annular conductive track 18. The central outer gear of the turntable serves as the driven gear 10, while the upper portion serves as the conductive posts 14 for the first, second, third, and fourth TIG welding guns 1, 2, 6, and 7. Conductive posts 14 are internally provided with wires connected to the first, second, third, and fourth annular conductive tracks 15, 16, 17, and 18, respectively. These posts are connected to the first, second, third, and fourth TIG welding guns 1, 2, 6, and 7, respectively, providing power input. The first annular conductive rail 15, the second annular conductive rail 16, the third annular conductive rail 17, and the fourth annular conductive rail 18 are in contact with the first brush 19, the second brush 20, the third brush 21, and the fourth brush 22, respectively, and are electrically connected to the power supply through the wires passing through the base 5. Figure 4 shown.

[0036] The motor 13 that provides the rotating power for the turntable 4 is fixed on the base 5. The output shaft 12 of the motor 13 transmits the power through the mutually meshing driving gear 11 and the driven gear 10. Figure 3 The driving gear 11 is located in the cavity of the base 5 and is fixedly connected to the output shaft 12.

[0037] The turntable 4 is connected to the base 5 via a second bearing 9, thereby achieving a rotatable connection between the turntable 4 and the base 5. The wire feeding gun 3 is connected to the turntable 4 via a first bearing 8, thereby achieving that the wire feeding gun 3 is fixed relative to the base 5 but can rotate relative to the turntable 4.

[0038] The first TIG welding gun 1, the second TIG welding gun 2, the third TIG welding gun 6, and the fourth TIG welding gun 7 are all identical TIG welding guns, each comprising a gun body and a tungsten electrode assembly disposed on the gun body. The tungsten electrode assembly comprises a welding gun barrel, a tungsten electrode clamp, a tungsten electrode 23, and a ceramic nozzle. The welding gun barrel and the ceramic nozzle are connected by threads. The tungsten electrode clamp is mounted inside the welding gun barrel and axially fixed by the ceramic nozzle. The tungsten electrode 23 is mounted inside the tungsten electrode clamp and locked by a tapered surface.

[0039] The tip of the tungsten electrode 23 is bent inward and faces the wire feeding gun 3. The tungsten electrodes of one group of TIG welding guns are symmetrically bent to guide the arc and intersect with the arc of the other group of TIG welding guns at the front end of the welding wire.

[0040] The wire feeding gun includes a gas protection mechanism and a cooling mechanism. The gas protection mechanism is located between the wire feeding nozzle and the wire feeding tube of the wire feeding gun, and the cooling mechanism is located between the TIG welding gun and the wire feeding gun.

[0041] There are two ways to connect the two sets of TIG welding guns in this invention:

[0042] First, in dual power supply mode, the four tungsten electrodes are powered by two DC pulse power supplies. A group of oppositely arranged TIG welding guns are connected to one power supply, and the two TIG welding guns in each group are connected to the positive and negative poles respectively. By controlling the phase difference between the two pulse currents, the arc can be better conducted to achieve the effect of resisting interference between the two arcs.

[0043] Second, in single power supply mode, four tungsten electrodes are powered by one power supply, where four TIG welding guns are connected to the positive pole and the welding wire is connected to the negative pole to resist arc interference.

[0044] In the dual power supply mode, the welding method of the quad-tungsten pole rotary additive manufacturing device provided by the present invention comprises the following steps:

[0045] Adjust the position of the wire feed gun and TIG welding gun to focus on the front end of the welding wire and plan the additive manufacturing path;

[0046] Turn on the gas, liquid and electric switches to start the additive process. A group of relatively set TIG welding guns are connected to a power supply. The two TIG welding guns in each group are connected to the positive and negative poles respectively. Two transverse pulse arcs are formed in the additive manufacturing process. The turntable drives the four TIG welding guns to rotate around the wire feed gun, forming a rotating arc during welding. The welding wire is melted in the process of rotating arc. At the same time, under the combined action of cutting during the rotation of the rotating arc and gravity, it becomes molten droplets of controllable size and drips downwards.

[0047] In a single power supply mode, the welding method of the quad-tungsten pole rotary additive manufacturing device provided by the present invention comprises the following steps:

[0048] Adjust the position of the wire feed gun and TIG welding gun to focus on the front end of the welding wire and plan the additive manufacturing path;

[0049] Turn on the gas, liquid and electric switches to start the additive process. Four TIG welding guns are connected to the positive pole and the welding wire is connected to the negative pole. Four transverse pulse arcs are formed during the additive manufacturing process. The turntable drives the four TIG welding guns to rotate around the wire feed gun, forming a rotating arc during welding. The welding wire is melted in the process of rotating arc. At the same time, under the combined action of cutting during the rotation of the rotating arc and gravity, it becomes molten droplets of controllable size and drips downward.

[0050] The four-tungsten-electrode rotary additive manufacturing device provided by the present invention can overcome the adsorption effect of the welding wire on the molten droplet. By changing the lateral force of the molten droplet through the rotating arc, it selectively cuts it according to the rotation speed during its growth process, thereby achieving precise control of the molten droplet size. Specifically, the rotating arc generated between the specific tungsten electrodes of the rotating welding gun is used as a heat source to melt the welding wire. No current loop is formed with the welding workpiece, and no molten pool is formed, which prevents the molten pool from affecting the molten droplet transition. Since the force of the rotating arc on the molten droplet is located in the horizontal plane and is evenly distributed around the molten droplet, and then acts together with gravity, the molten droplet can be selected to drip at a certain moment of growth according to the control of the rotation speed. The molten droplet transition is stable and the additive shape control effect is good.

[0051] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A quad-tungsten pole rotating additive manufacturing device, characterized in that: The invention comprises a base (5), a turntable (4), a wire feeding gun (3), four TIG welding guns, a circuit system, a motor (13) and a transmission gear set, wherein the motor (13) is fixed on the base (5), and the output shaft (12) of the motor (13) is connected to the turntable (4) through the transmission gear set, the turntable (4) is rotatably mounted on the base (5), the wire feeding gun (3) passes through the center of the turntable (4) and is fixedly mounted on the base (5), and the turntable (4) is rotatable around the wire feeding gun (3); Four TIG welding guns are evenly distributed around the wire feeding gun (3) and are arranged on the turntable (4). The four TIG welding guns are symmetrically arranged with the wire feeding gun (3) as the center. The tungsten electrodes (23) of the four TIG welding guns face the welding wire fed by the wire feeding gun (3). The four TIG welding guns and the wire feeding gun (3) are electrically connected to a power source via a circuit system that penetrates the base (5) and the turntable (4).

2. The quadruple tungsten pole rotating additive manufacturing device according to claim 1, characterized in that: The turntable (4) and the base (5) are rotatably connected via a second bearing (9), and the wire feeding gun (3) and the turntable (4) are rotatably connected via a first bearing (8); the gear set comprises a driven gear (10) fixedly connected to the turntable (4) and a driving gear (11) fixedly connected to the output shaft (12), and the driven gear (10) and the driving gear (11) are meshed with each other.

3. The quadruple tungsten pole rotating additive manufacturing device according to claim 1, characterized in that: The circuit system comprises a conductive pile (14) capable of rotating together with the turntable (4); four annular conductive rails are arranged on the outer circumference of the conductive pile (14) and surround the conductive pile (14); wires are arranged inside the conductive pile and are connected to four TIG welding guns respectively. The four annular conductive rails are respectively in contact with an electric brush and are electrically connected to a power source via a wire that passes through the base (5).

4. The quadruple tungsten pole rotary additive manufacturing device according to claim 1, characterized in that: The four TIG welding guns are arranged opposite to each other in pairs, and the connection line between the tungsten electrodes (23) of the two TIG welding guns arranged opposite to each other in each group passes through the front end of the welding wire; the four TIG welding guns are arranged to be inclined toward the wire feeding gun (3), and the connection between the four TIG welding guns and the rotating disk (4) is detachable, and the distance between the wire feeding guns is adjustable.

5. The quadruple tungsten pole rotating additive manufacturing device according to claim 1, characterized in that: The TIG welding gun comprises a gun body and a tungsten electrode assembly arranged on the gun body, the tungsten electrode assembly comprises a welding gun tube, a tungsten electrode clamp, a tungsten electrode (23), and a ceramic nozzle, the welding gun tube and the ceramic nozzle are connected by threads, the tungsten electrode clamp is installed inside the welding gun tube and is axially fixed by the ceramic nozzle, and the tungsten electrode (23) is installed inside the tungsten electrode clamp and is locked by a conical surface.

6. The quadruple tungsten pole rotary additive manufacturing device according to claim 5, characterized in that: The tip of the tungsten electrode (23) is bent inwardly and faces the wire feeding gun (3).

7. The quadruple tungsten pole rotating additive manufacturing device according to claim 1, characterized in that: The wire feeding gun (3) comprises a gas protection mechanism and a cooling mechanism, wherein the gas protection mechanism is located between a wire feeding nozzle and a wire feeding tube of the wire feeding gun (3), and the cooling mechanism is located between the TIG welding gun and the wire feeding gun (3).

8. The quadruple tungsten pole rotating additive manufacturing device according to claim 1, characterized in that: The four tungsten electrodes are powered by two DC pulse power supplies, one group of two TIG welding guns arranged opposite to each other are respectively connected to the positive and negative poles of one power supply, and the other group of two TIG welding guns arranged opposite to each other are respectively connected to the positive and negative poles of another power supply.

9. The quadruple tungsten pole rotary additive manufacturing device according to claim 1, characterized in that: The four tungsten electrodes are powered by a power supply, the four TIG welding guns are all connected to the positive electrode of the same power supply, and the welding wires are connected to the negative electrode of the power supply.

10. The additive manufacturing method of the quadruple tungsten pole rotating additive manufacturing device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Adjust the wire feeding gun (3) and the TIG welding gun position to focus on the front end of the welding wire and plan the additive manufacturing path; In the dual power supply mode, the gas, liquid and electric switches are turned on to start the additive manufacturing process. A group of TIG welding guns arranged opposite to each other are respectively connected to the positive and negative poles of one power supply, and another group of TIG welding guns arranged opposite to each other are respectively connected to the positive and negative poles of another power supply. Two transverse pulse arcs are formed during the additive manufacturing process. The turntable (4) drives the four TIG welding guns to rotate around the wire feeding gun (3), forming a rotating arc during welding. The welding wire is melted in the process of the rotating arc, and at the same time, the cutting during the rotation of the rotating arc and the combined effect of gravity turn into molten droplets of controllable size and drip downward. In the single power mode, the gas, liquid and electric switches are turned on to start the additive process. Four TIG welding guns are connected to the positive electrode and the welding wire is connected to the negative electrode. Four transverse pulse arcs are formed during the additive manufacturing process. The turntable (4) drives the four TIG welding guns to rotate around the wire feeding gun (3). A rotating arc is formed during welding. The welding wire is melted in the process of the rotating arc. At the same time, the cutting during the rotation of the rotating arc and the combined effect of gravity turn into molten droplets of controllable size and drip downward.

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