Welding device

Abstract

To secure a penetration amount of a workpiece while suppressing deterioration in shield property by a shield gas.SOLUTION: A first nozzle 31 is disposed so as to surround an outer peripheral part of a contact tip 35 to form a first gas passage 36 between the contact tip 35 and the first nozzle. A second nozzle 32 is disposed so as to surround an outer peripheral part of the first nozzle 31 to form a second gas passage 37 between the first nozzle 31 and the second nozzle. A flow velocity of a first shield gas G1 jetted to a workpiece W from the first gas passage 36 is faster than a flow velocity of a second shield gas G2 jetted to the workpiece W from the second gas passage 37.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a welding device. [Background technology]

[0002] Patent Document 1 discloses a welding torch that includes a contact tip and a nozzle that is arranged so as to surround the contact tip.

[0003] In the invention of Patent Document 1, a shielding gas is supplied through the space between the contact tip and the nozzle, and arc welding is performed in a state in which the shielding gas is diffused from the tip of the torch. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3314595 Summary of the Invention [Problem to be solved by the invention]

[0005] In arc welding, there is a demand for sufficient penetration of the workpiece. The inventors of the present invention have investigated ways to increase the penetration of the workpiece by increasing the flow rate of the shielding gas, thereby narrowing the arc shape and increasing the energy density.

[0006] However, simply increasing the flow rate of the shielding gas narrows the spread of the shielding gas, which may result in a deterioration in the shielding effect of the shielding gas at the welding position of the workpiece.

[0007] The present invention has been made in view of the above points, and its object is to ensure the penetration amount of the workpiece while suppressing deterioration of the shielding property due to the shielding gas. [Means for solving the problem]

[0008] A first invention is a welding device equipped with a welding torch that supplies welding wire to a workpiece, the welding torch having a contact tip that supplies power to the welding wire to generate an arc between the workpiece and the welding wire, a first nozzle that is arranged to surround the outer periphery of the contact tip and forms a first gas flow path between the contact tip and the first nozzle, and a second nozzle that is arranged to surround the outer periphery of the first nozzle and forms a second gas flow path between the first nozzle and the first nozzle, the welding device also having a gas supply unit that supplies a first shielding gas and a second shielding gas to the first gas flow path and the second gas flow path, respectively, and the flow velocity of the first shielding gas blown from the first gas flow path to the workpiece is faster than the flow velocity of the second shielding gas blown from the second gas flow path to the workpiece.

[0009] In the first aspect of the present invention, the first shielding gas blown out from the first gas passage narrows the shape of the arc, increasing the energy density and ensuring a sufficient penetration amount into the workpiece.

[0010] Furthermore, the second shielding gas blown out from the second gas flow passage sufficiently shields the area around the welding position of the workpiece, thereby preventing the shielding performance from deteriorating.

[0011] A second aspect of the present invention is the welding device of the first aspect, wherein an opening area of ​​the first gas flow passage is smaller than an opening area of ​​the second gas flow passage.

[0012] In the second aspect of the present invention, the flow velocity of the first shielding gas blown out from the first gas passage can be made faster than the flow velocity of the shielding gas blown out from the second gas passage.

[0013] A third invention is the welding device according to the first or second invention, wherein the outer periphery of the contact tip is formed in a tapered shape that narrows toward the tip side.

[0014] In the third aspect of the present invention, the flow passage area between the tapered portion of the contact tip and the first nozzle is increased, allowing the shielding gas to flow smoothly within the first gas passage.

[0015] A fourth invention is the welding device according to the first or second invention, wherein a tip of the first nozzle protrudes further toward the work than a tip of the second nozzle.

[0016] In the fourth aspect of the present invention, the flow of the second shielding gas blown out from the second gas passage can be prevented from being disturbed by the first shielding gas blown out from the first gas passage.

[0017] Furthermore, even when the attitude of the welding torch is changed, the tip of the second nozzle can be prevented from interfering with the workpiece.

[0018] A fifth invention is the welding apparatus of the first or second invention, wherein the gas supply unit includes a first gas supply unit and a second gas supply unit, the first gas supply unit having a first gas cylinder in which the first shielding gas is stored, a first pipe connecting the first gas cylinder and the first gas flow path, and a first flow rate control valve that adjusts the flow rate of the first shielding gas flowing through the first pipe, and the second gas supply unit has a second gas cylinder in which the second shielding gas is stored, a second pipe connecting the second gas cylinder and the second gas flow path, and a second flow rate control valve that adjusts the flow rate of the second shielding gas flowing through the second pipe.

[0019] In the fifth invention, by adjusting the opening degree of the first flow rate adjustment valve and the opening degree of the second flow rate adjustment valve, respectively, the flow velocity of the first shielding gas blown out from the first gas flow path can be made faster than the flow velocity of the second shielding gas blown out from the second gas flow path.

[0020] A sixth aspect of the present invention is the welding device according to the first or second aspect of the present invention, further comprising a laser head that emits a laser beam to the workpiece.

[0021] In the sixth aspect of the present invention, the plume generated during laser welding can be removed from the optical axis of the laser head by the first shielding gas with a high flow rate. [Effects of the Invention]

[0022] According to the present invention, it is possible to ensure the penetration amount of the workpiece while suppressing deterioration of the shielding property due to the shielding gas. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a diagram showing a configuration of a welding device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of a welding torch. [Figure 3] FIG. 2 is a cross-sectional view showing the periphery of a welding position of a workpiece. [Figure 4] FIG. 2 is a cross-sectional view showing the shape of the tip of a welding torch. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0025] As shown in FIG. 1, the welding device 1 includes a laser welding unit 10, an arc welding unit 20, a robot 50, and a control unit 55.

[0026] The laser welding unit 10 has a laser oscillator 5, a transmission fiber 6, and a laser head 11. The laser oscillator 5 outputs laser light LB based on a command from a control unit 55. The laser oscillator 5 and the laser head 11 are connected by the transmission fiber 6. The laser light LB is transmitted from the laser oscillator 5 to the laser head 11 via the transmission fiber 6.

[0027] The laser head 11 is attached to the tip of the arm of the robot 50. The laser head 11 irradiates the workpiece W with laser light LB based on a command from the control unit 55.

[0028] As shown in FIG. 2, the arc welding unit 20 includes a wire feeder 21, a welding torch 30, and a gas supplier 40.

[0029] Wire feeder 21 has a feed roller 22. Wire feeder 21 rotates feed roller 22 to feed welding wire 23 downstream in the feed direction.

[0030] Welding torch 30 supplies welding wire 23, which is fed from wire feeder 21, to workpiece W. Welding torch 30 welds workpiece W by generating an arc between welding wire 23, which is a consumable electrode, and workpiece W. Welding torch 30 is attached to laser welding unit 10 via support arm 7.

[0031] Welding torch 30 has a first nozzle 31, a second nozzle 32, and a contact tip 35. Contact tip 35 supplies power to welding wire 23 to generate an arc 60 between the welding wire 23 and workpiece W (see FIG. 3). Welding wire 23 is inserted through contact tip 35.

[0032] The first nozzle 31 is disposed so as to surround the outer periphery of the contact tip 35. Between the first nozzle 31 and the contact tip 35, a first gas flow path 36 is formed.

[0033] The second nozzle 32 is disposed so as to surround the outer periphery of the first nozzle 31. Between the second nozzle 32 and the first nozzle 31, a second gas flow path 37 is formed.

[0034] The gas supply unit 40 includes a first gas supply unit 41 and a second gas supply unit 45. The first gas supply unit 41 supplies a first shielding gas G1 (see FIG. 3) to the first gas passage 36. The second gas supply unit 45 supplies a second shielding gas G2 (see FIG. 3) to the second gas passage 37.

[0035] The first gas supply unit 41 includes a first gas cylinder 42 , a first pipe 43 , and a first flow rate adjustment valve 44 .

[0036] A first shielding gas G1 is stored in the first gas cylinder 42. The first shielding gas G1 is, for example, helium gas, argon gas, or a mixture thereof. A first pipe 43 connects the first gas cylinder 42 to the first gas flow path 36. A first flow rate adjustment valve 44 adjusts the flow rate of the first shielding gas G1 flowing through the first pipe 43.

[0037] The second gas supply unit 45 includes a second gas cylinder 46, a second pipe 47, and a second flow rate adjustment valve 48.

[0038] A second shielding gas G2 is stored in the second gas cylinder 46. The second shielding gas G2 is, for example, helium gas, argon gas, or a mixture thereof. A second pipe 47 connects the second gas cylinder 46 to the second gas flow path 37. A second flow rate adjustment valve 48 adjusts the flow rate of the second shielding gas G2 flowing through the second pipe 47.

[0039] 1, robot 50 moves laser head 11 and welding torch 30 in a predetermined welding direction based on commands from control unit 55. This allows laser welding and arc welding to be performed in the welding area of ​​workpiece W while moving the irradiation position of laser beam LB and the supply position of welding wire 23.

[0040] Control unit 55 controls the operations of laser welding unit 10, arc welding unit 20, and robot 50. Control unit 55 also has a function of controlling the start and stop of output of laser light LB, the output intensity of laser light LB, the feed speed of welding wire 23, etc., in addition to the movement speed of laser head 11 and welding torch 30 by robot 50.

[0041] <Shielding gas flow rate> In arc welding, there is a demand for sufficient penetration of the workpiece W. Here, it is conceivable to increase the flow rate of the shielding gas to narrow the arc shape and increase the energy density, thereby increasing the penetration of the workpiece W.

[0042] However, simply increasing the flow rate of the shielding gas may narrow the spread of the shielding gas, which may result in a deterioration in the shielding effect of the shielding gas at the welding position of the workpiece W.

[0043] Therefore, in this embodiment, it is possible to ensure the penetration amount of the workpiece W while suppressing the deterioration of the shielding property due to the shielding gas.

[0044] 3, the tip of the first nozzle 31 extends closer to the workpiece W than the tip of the contact tip 35. A cover portion 31a that covers the tip of the contact tip 35 is provided at the tip of the first nozzle 31. The cover portion 31a has blowout holes 31b through which the welding wire 23 is inserted and through which the first shielding gas G1 is blown out.

[0045] 4, when the diameter D1 of the welding wire 23 is 1.2 mm, it is preferable to set the inner diameter D2 of the blowout hole 31b to approximately 2.4 to 3.4 mm. Note that the inner diameter D2 of the blowout hole 31b may be set to approximately 3.5 to 4.5 mm, taking into consideration the bending tendency of the welding wire 23. This increases the flow velocity of the first shielding gas G1 passing through the first gas flow passage 36 as it passes through the blowout hole 31b.

[0046] Furthermore, when the amount of protrusion L1 of the welding wire 23 from the tip of the contact tip 35 is 15 mm, it is preferable to set the distance L2 between the tip surface of the contact tip 35 and the tip surface of the cover portion 31a to a maximum of approximately 5 mm. This makes it possible to prevent the first nozzle 31 from coming too close to the arc 60 and melting the first nozzle 31.

[0047] The second nozzle 32 extends linearly along the outer periphery of the first nozzle 31. This allows the second shielding gas G2 passing through the second gas flow passage 37 to be blown over a wide area toward the welding position of the workpiece W. The outer diameter of the first nozzle 31 is, for example, φ9.5 mm, and the inner diameter of the second nozzle 32 is, for example, φ18 mm.

[0048] In this embodiment, the opening area of ​​the first gas flow passage 36 is smaller than the opening area of ​​the second gas flow passage 37. In this way, the flow velocity of the first shielding gas G1 blown from the first gas flow passage 36 to the workpiece W can be made faster than the flow velocity of the second shielding gas G2 blown from the second gas flow passage 37 to the workpiece W.

[0049] This allows the shape of the arc 60 to be narrowed and the energy density to be increased by the first shielding gas G1 blown out from the first gas flow path 36. As a result, it is possible to ensure a sufficient penetration amount of the workpiece W and increase the welding speed.

[0050] Furthermore, the second shielding gas G2 blown out from the second gas flow passage 37 sufficiently shields the area around the welding position of the workpiece W, thereby preventing the shielding performance from deteriorating.

[0051] In addition, by adjusting the opening degree of the first flow control valve 44 and the opening degree of the second flow control valve 48, the flow rate of the first shielding gas blown out from the first gas flow passage 36 may be made faster than the flow rate of the second shielding gas blown out from the second gas flow passage 37.

[0052] Here, the flow velocity of the first shielding gas is preferably set to, for example, about 5 to 15 m / sec, and the flow velocity of the second shielding gas is preferably set to, for example, about 1.5 to 2 m / sec.

[0053] Specifically, when laser welding is performed by emitting laser light LB to the workpiece W, the workpiece W melts and generates a plume 61. If the plume 61 generated during laser welding remains on the optical axis of the laser head 11, the output of the laser light LB will decrease, and there is a risk that the penetration depth of the workpiece W will become shallow.

[0054] Furthermore, if the plume 61 generated during laser welding adheres to the optical system of the laser head 11, there is a risk that the quality of the laser welding process will be reduced or that a malfunction of the device will occur.

[0055] In contrast, in this embodiment, the first shielding gas G1, which has a high flow rate, can remove the plume 61 generated during laser welding from the optical axis of the laser head 11. This can prevent a decrease in the processing quality of the laser welding.

[0056] The outer periphery of the contact tip 35 is tapered toward the tip, which increases the flow path area between the tapered portion of the contact tip 35 and the first nozzle 31, allowing the first shielding gas G1 to flow smoothly within the first gas flow path 36.

[0057] The tip of the first nozzle 31 protrudes further toward the workpiece W than the tip of the second nozzle 32. This prevents the flow of the second shielding gas G2 blown out from the second gas passage 37 from being disturbed by the first shielding gas G1 blown out from the first gas passage 36.

[0058] Furthermore, even when the robot 50 changes the posture of the welding torch 30, the tip of the second nozzle 32 can be prevented from interfering with the workpiece W. [Industrial Applicability]

[0059] As described above, the present invention has the highly practical effect of being able to ensure the amount of penetration of the workpiece while suppressing the deterioration of shielding properties due to shielding gas, and is therefore extremely useful and has high industrial applicability. [Explanation of symbols]

[0060] 1. Welding equipment 11 Laser head 23 Welding wire 30 Welding Torch 31 No. 1 nozzle 32 Second nozzle 35 Contact Tip 36 First gas flow path 37 Second gas flow path 40 Gas supply unit 41 First gas supply unit 42 No. 1 Gas Cylinder 43 First Pipe 44 First flow control valve 45 Second gas supply section 46 Second Gas Cylinder 47 Second piping 48 Second flow control valve 60 Arc G1 First shielding gas G2 Second shielding gas LB laser light double work

Claims

1. A welding device having a welding torch that supplies welding wire to a workpiece, The welding torch is a contact tip that supplies power to the welding wire to generate an arc between the welding wire and the workpiece; a first nozzle disposed to surround an outer periphery of the contact tip and forming a first gas flow path between the contact tip and the first nozzle; a second nozzle disposed so as to surround an outer periphery of the first nozzle and forming a second gas flow path between the first nozzle and the second nozzle; a gas supply unit that supplies a first shielding gas and a second shielding gas to the first gas flow path and the second gas flow path, respectively; The flow velocity of the first shielding gas blown onto the workpiece from the first gas passage is faster than the flow velocity of the second shielding gas blown onto the workpiece from the second gas passage. Welding equipment.

2. The welding device of claim 1, The opening area of ​​the first gas flow path is smaller than the opening area of ​​the second gas flow path. Welding equipment.

3. The welding device according to claim 1 or 2, The outer periphery of the contact tip is tapered toward the tip. Welding equipment.

4. The welding device according to claim 1 or 2, The tip of the first nozzle protrudes toward the workpiece more than the tip of the second nozzle. Welding equipment.

5. The welding device according to claim 1 or 2, the gas supply unit includes a first gas supply unit and a second gas supply unit; The first gas supply unit is a first gas cylinder storing the first shielding gas; a first pipe connecting the first gas cylinder and the first gas flow path; a first flow rate adjusting valve that adjusts the flow rate of the first shielding gas flowing through the first pipe, The second gas supply unit is a second gas cylinder in which the second shielding gas is stored; a second pipe connecting the second gas cylinder and the second gas flow path; a second flow rate adjusting valve that adjusts the flow rate of the second shielding gas flowing through the second pipe. Welding equipment.

6. The welding device according to claim 1 or 2, a laser head for emitting laser light to the workpiece; Welding equipment.

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