Arc welding apparatus, tips, and arc welding method
The arc welding apparatus adjusts wire spacing through protrusion length adjustment, addressing the inefficiency of tip replacement for bead width changes, ensuring stable and efficient welding operations.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2025-01-08
- Publication Date
- 2026-07-21
AI Technical Summary
Conventional arc welding methods require replacing the contact tip to adjust the distance between wires for changing the bead width, leading to increased labor and inefficiency.
An arc welding apparatus with adjustable insertion holes for the first and second wires, allowing the distance between the wire tips to be adjusted by changing the protrusion length without replacing the tip.
Enables changing the outer diameter of the bridge droplet without replacing the tip, facilitating stable welding with appropriate bead width and reducing labor.
Smart Images
Figure 2026119868000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an arc welding apparatus, a tip, and an arc welding method.
Background Art
[0002] Patent Document 1 discloses a laminated molding contact tip that forms a bridge droplet between a first wire (first wire electrode) fed through a first hole and a second wire (second wire electrode) fed through a second hole.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Here, the smaller the distance between the first wire and the second wire, the smaller the outer diameter of the bridge droplet and the smaller the bead width. On the other hand, the larger the distance between the first wire and the second wire, the larger the outer diameter of the bridge droplet and the larger the bead width.
[0005] Therefore, in the conventional invention, when attempting to change the distance between the first wire and the second wire in order to change the bead width of the weld bead, it is necessary to replace the contact tip with another contact tip having a different distance between the first wire and the second wire, resulting in a problem of increased labor.
[0006] The present invention has been made in view of such points, and an object thereof is to be able to change the outer diameter of the bridge droplet generated by bridging between the first wire and the second wire without performing the operation of replacing the tip.
Means for Solving the Problems
[0007] The first invention is an arc welding apparatus comprising: a wire feeding unit that feeds a first wire and a second wire, which are consumable electrodes, toward a base material; and a welding torch that generates an arc between the first wire, the second wire and the base material to weld the base material, wherein the welding torch has a tip through which the first wire is inserted and a second insertion hole formed at a position away from the first insertion hole through which the second wire is inserted, the first insertion hole and the second insertion hole extend in a direction in which the distance between them decreases toward the tip of the tip, and the tips of the first wire and the second wire protruding from the tip are arranged at a predetermined distance apart.
[0008] In the first invention, the first insertion hole and the second insertion hole extend in a direction in which the distance between them decreases as they approach the tip of the tip. Therefore, the distance between the tip of the first wire and the tip of the second wire can be adjusted by changing the protrusion length of the first wire and the second wire from the tip.
[0009] This allows the outer diameter of the bridge droplets formed by the bridging of the first and second wires to be changed, without the need to change the tip, and enables welding the base material with an appropriate bead width.
[0010] The second invention is an arc welding apparatus of the first invention, wherein the protrusion lengths of the first wire and the second wire from the tip are 3 mm or more and 20 mm or less, and the wire angle between the first wire and the second wire is 3° or more and 6° or less.
[0011] In the second invention, welding operations can be performed stably by setting the parameters to satisfy the above-mentioned conditions.
[0012] Specifically, if the wire protrusion length is less than 3 mm, there is a risk that the molten first and second wires will adhere to the tip. If the protrusion length is greater than 20 mm, the tips of the first and second wires may wobble, potentially causing instability in the welding position. Therefore, the wire protrusion length is set to be between 3 mm and 20 mm.
[0013] Furthermore, the wire angle is set in accordance with the lower and upper limits of the wire protrusion length. Generally, the wire protrusion length is set to be between 15mm and 25mm. If the wire angle is less than 3°, the wire protrusion length will exceed 25mm. If the wire angle is greater than 6°, the wire protrusion length will be less than 15mm. Therefore, the wire angle is set to be between 3° and 6°.
[0014] The third invention is a tip for supplying power to a first wire and a second wire, which are consumable electrodes, wherein the tip has a first insertion hole through which the first wire is inserted and a second insertion hole located away from the first insertion hole through which the second wire is inserted, and the first insertion hole and the second insertion hole extend in a direction in which the distance between them decreases as they move toward the tip of the tip.
[0015] In the third invention, the first and second insertion holes extend in a direction in which the distance between them decreases as they approach the tip of the tip. Therefore, the distance between the tip of the first wire and the tip of the second wire can be adjusted by changing the protrusion length of the first and second wires from the tip.
[0016] The fourth invention is an arc welding method comprising the steps of feeding a first wire and a second wire, which are consumable electrodes, from a tip toward a base material, and changing the wire spacing at the tips of the first wire and the second wire according to the protrusion length of the first wire and the second wire from the tip.
[0017] In the fourth invention, the wire spacing between the first wire and the second wire can be adjusted according to the protruding lengths of the first wire and the second wire from the chip.
[0018] The fifth invention is the arc welding method of the fourth invention. In the step of changing the wire spacing, the larger the protruding length is, the smaller the wire spacing is.
[0019] In the fifth invention, the wire spacing can be reduced by increasing the protruding lengths of the first wire and the second wire from the chip.
Advantages of the Invention
[0020] According to the present invention, without performing the operation of replacing the chip, the outer diameter of the bridge droplet generated by the bridging of the first wire and the second wire can be changed.
Brief Description of the Drawings
[0021] [Figure 1] It is a side view showing the configuration of the arc welding apparatus. [Figure 2] It is a perspective view showing the configuration of the welding torch. [Figure 3] It is a side cross-sectional view showing a state where a bridge droplet is formed between the first wire and the second wire. [Figure 4] It is a side cross-sectional view showing the configuration of the chip. [Figure 5] It is a diagram for explaining the relationship between the protruding lengths of the first wire and the second wire and the distance between the first wire and the second wire. [Figure 6] It is a graph showing the relationship between the wire spacing between the first wire and the second wire and the welding current. [Figure 7] It is a table showing the relationship among the welding current, the welding voltage, and the wire feeding amount. [Figure 8] It is a graph showing the relationship between the welding voltage and the arc length. [Figure 9]This diagram illustrates the changes in the protrusion lengths of the first and second wires in response to changes in welding current. [Figure 10] This graph shows the relationship between the protrusion lengths of the first and second wires and the wire spacing between the first and second wires. [Figure 11] This flowchart illustrates the procedure for adjusting the position of the chip relative to the base material. [Figure 12] This diagram compares the bead width of weld beads when arc welding is performed with different welding currents. [Figure 13] This diagram compares the bead width, bead height, and penetration of weld beads when arc welding is performed with a similar welding current but varying wire spacing. [Modes for carrying out the invention]
[0022] Embodiments of the present invention will be described below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses.
[0023] As shown in Figure 1, the arc welding apparatus 1 generates an arc 16 (see Figure 3) between the first wire 10 and the second wire 20, which are consumable electrodes, and the base material 50 to weld the base material 50.
[0024] The arc welding apparatus 1 comprises a robot 2, a control unit 5, a first wire reel 11, a second wire reel 21, a welding torch 30, and a wire feeding unit 40.
[0025] The first wire 10 is wound around the first wire reel 11. The first wire 10, which is drawn out from the first wire reel 11, is fed toward the base material 50 by the wire feeding unit 40.
[0026] The second wire 20 is wound around the second wire reel 21. The second wire 20, pulled out from the second wire reel 21, is fed toward the base material 50 by the wire feeding unit 40.
[0027] The wire feeding unit 40 feeds the first wire 10 and the second wire 20 toward the base material 50. Based on the signal from the control unit 5, the wire feeding unit 40 feeds the first wire 10 and the second wire 20 at a predetermined feeding amount (feeding speed).
[0028] Robot 2 has multiple joints. A welding torch 30 is attached to the tip of robot 2. Robot 2 moves the position of the welding torch 30 relative to the base material 50.
[0029] The control unit 5 controls the operation of the robot 2 and the wire feeding unit 40. The control unit 5 moves the welding torch 30 along the welding direction of the base material 50 by giving current commands to the motors (not shown) of each axis of the robot 2. The control unit 5 controls the feeding speed of the first wire 10 and the second wire 20 according to the preset welding current.
[0030] As shown in Figure 2, a first feeding path 12 and a second feeding path 22 are provided between the wire feeding unit 40 and the welding torch 30. The first wire 10 fed from the wire feeding unit 40 passes through the first feeding path 12. The second wire 20 fed from the wire feeding unit 40 passes through the second feeding path 22.
[0031] The welding torch 30 includes a torch body 31, a torch tip 32, a junction 34, and a tip 35 (see Figure 3).
[0032] The torch body 31 is formed in a cylindrical shape. The first wire 10 and the second wire 20 pass through the inside of the torch body 31. The torch tip 32 is provided on the tip side of the torch body 31.
[0033] The merging section 34 is provided on the base end side of the torch body 31. The merging section 34 merges the first wire 10, which has passed through the first feed path 12, and the second wire 20, which has passed through the second feed path 22, so that they pass through the torch body 31 and the torch tip 32.
[0034] As shown in Figure 3, the tip 35 is positioned inside the torch tip 32. The tip of the tip 35 protrudes from the torch tip 32. The tip 35 supplies power to the first wire 10 and the second wire 20.
[0035] The tips of the first wire 10 and the second wire 20 protruding from the tip 35 are positioned at a predetermined distance apart. When a welding current is applied to the first wire 10 and the second wire 20, a bridge occurs between the first wire 10 and the second wire 20, forming a bridge droplet 15. An arc 16 is generated between the bridge droplet 15 and the base material 50. The arc 16 forms a molten pool 17 in the base material 50. By performing arc welding with the bridge droplet 15 formed, the bead width can be increased.
[0036] In Figure 3, the symbol a is the protrusion length [mm] of the first wire 10 and the second wire 20 from the tip of the tip 35. The symbol b is the arc length [mm]. The symbol c is the distance [mm] between the first wire 10 and the second wire 20 at the tip of the tip 35. The symbol h is the distance [mm] from the tip of the tip 35 to the base material 50. The symbol x is the distance [mm] between the first wire 10 and the second wire 20 at the location where a bridging occurs between them.
[0037] As shown in Figure 4, the tip 35 has a first insertion hole 36 and a second insertion hole 37. The first wire 10 is inserted through the first insertion hole 36. The second insertion hole 37 is located at a distance from the first insertion hole 36. The second wire 20 is inserted through the second insertion hole 37.
[0038] The first insertion hole 36 and the second insertion hole 37 extend in a direction in which the distance between them decreases as they approach the tip of the tip 35. In the example shown in Figure 4, the first insertion hole 36 and the second insertion hole 37 are positioned point-symmetrically with respect to the axis of the tip 35. The first insertion hole 36 and the second insertion hole 37 are inclined in a direction that approaches the center line of the tip 35 as they approach the tip of the tip 35.
[0039] With this configuration, the wire spacing x between the tip of the first wire 10 and the tip of the second wire 20 can be adjusted by changing the protrusion length a of the first wire 10 and the second wire 20 from the tip 35.
[0040] This allows the outer diameter of the bridge droplet 15, which is formed when the first wire 10 and the second wire 20 become entangled, to be changed without having to replace the tip 35, and the base material 50 to be welded with an appropriate bead width.
[0041] In Figure 5, the symbol L is the distance [mm] from the tip of the tip 35 to the point where the first wire 10 and the second wire 20 protruding from the tip 35 meet. The symbol θ is the wire angle [°] between the first wire 10 passing through the first insertion hole 36 and the second wire 20 passing through the second insertion hole 37. The symbols a, c, and x were explained in Figure 3 and are therefore omitted here.
[0042] Here, the protrusion length a of the first wire 10 and the second wire 20 from the tip of the tip 35 can be calculated by the following equation (1).
[0043] a=(cx) / (2·tan(θ / 2)) ···(1) Figure 6 is a graph showing the relationship between the wire spacing x of the first wire 10 and the second wire 20 and the welding current E. As shown in Figure 6, the larger the wire spacing x of the first wire 10 and the second wire 20, the larger the welding current E becomes.
[0044] Figure 7 is a table showing the relationship between welding current E, welding voltage V, and wire feed rate s. In the example in Figure 7, the wire diameters of the first wire 10 and the second wire 20 are assumed to be φ0.9 mm. As shown in Figure 7, the larger the welding current E, the larger the welding voltage V and wire feed rate s become.
[0045] Figure 8 is a graph showing the relationship between welding voltage V and arc length b. As shown in Figure 8, the larger the welding voltage V, the larger the arc length b. Also, the larger the wire feed rate s, the higher the welding voltage V required to maintain the same arc length b.
[0046] Figure 9 illustrates the change in the protrusion length a of the first wire 10 and the second wire 20 with respect to a change in welding current E. As shown in Figure 9, when the welding current E is 330A, the protrusion length is a1 and the distance between the first wire 10 and the second wire 20 is x1. When the welding current E is 300A, the protrusion length is a2 and the distance between the first wire 10 and the second wire 20 is x2. When the welding current E is 250A, the protrusion length is a3 and the distance between the first wire 10 and the second wire 20 is x3. In this case, a1 <a2<a3、x1> x2 > x3.
[0047] Figure 10 is a graph showing the relationship between the protrusion length a of the first wire 10 and the second wire 20 and the wire spacing x between the first wire 10 and the second wire 20. As shown in Figure 10, the larger the protrusion length a, the smaller the wire spacing x becomes.
[0048] The following describes the procedure for adjusting the position of the tip 35 relative to the base material 50. As shown in Figure 11, in step S11, the distance h from the tip of the tip 35 to the base material 50 during arc welding is determined, and the process proceeds to step S12. In the example shown in this embodiment, for example, h = 15 mm.
[0049] In step S12, the welding current E is set, and the process proceeds to step S13.
[0050] Specifically, when the thickness of the base material 50 is 6.0 mm, it is preferable to set the welding current E in the range of 220 to 260 A. When the thickness of the base material 50 is 8.0 mm, it is preferable to set the welding current E in the range of 280 to 300 A. When the thickness of the base material 50 is 10.0 mm, it is preferable to set the welding current E in the range of 320 to 340 A. In the example shown in this embodiment, for example, E = 300 A.
[0051] In step S13, based on the table showing the welding waveform in Figure 7, the wire feed rate s and welding voltage V corresponding to the set welding current E are extracted, and the process proceeds to step S14. In the example shown in this embodiment, when the welding current E is 300A, the voltage V is 30.2V and the wire feed rate s is 8m / min.
[0052] In step S14, the protrusion length a of the first wire 10 and the second wire 20 is calculated, and the process proceeds to step S15.
[0053] Specifically, in the example shown in this embodiment, the distance c between the first wire 10 and the second wire 20 at the tip of the tip 35 is 1.5 mm. The wire angle θ between the first wire 10 passing through the first insertion hole 36 and the second wire 20 passing through the second insertion hole 37 is 6°.
[0054] Furthermore, when the welding current E is 300A, the wire spacing x becomes 0.6mm, as shown in Figure 6. Thus, the overhang length a can be calculated using equation (1) above. Specifically, in the example shown in this embodiment, a = 8.5mm.
[0055] In step S15, the arc length b is calculated based on the welding voltage V, and the process proceeds to step S16. In the example shown in this embodiment, when the voltage V is 30.2V and the feed rate s is 8m / min, the arc length b is 6.0mm, as shown in Figure 8.
[0056] In step S16, the distance h' = a + b is calculated, and the process proceeds to step S17. Specifically, h' = 8.5 + 6 = 14.5 [mm].
[0057] In step S17, it is determined whether h'=h. If the determination in step S17 is "YES", the welding preparation is considered complete and the process ends. If the determination in step S17 is "NO", the process branches to step S18.
[0058] In step S18, as shown in Figure 8, the distance between the tip 35 and the base material 50 is adjusted by changing the arc length b by adjusting the welding voltage V, so that h'=h, and the process is completed.
[0059] Specifically, since the calculated distance h' is h' = 14.5 [mm] and the target distance h is h = 15 [mm], we can adjust the welding voltage V so that the arc length b is 6.5 mm, resulting in h' = 8.5 + 6.5 = 15 [mm], and thus h' = h.
[0060] In this embodiment, the protrusion length a of the first wire 10 and the second wire 20 from the tip 35 is preferably 3 mm or more and 20 mm or less. Furthermore, the wire angle θ between the first wire 10 and the second wire 20 is preferably 3° or more and 6° or less.
[0061] By setting the system to meet the above-mentioned conditions, welding operations can be performed stably.
[0062] Specifically, if the protrusion length a is less than 3 mm, the molten first wire 10 and second wire 20 may adhere to the tip 35. If the protrusion length a is greater than 20 mm, the tips of the first wire 10 and second wire 20 may wobble, potentially causing instability in the welding position. Therefore, the wire protrusion length is set to be between 3 mm and 20 mm.
[0063] Furthermore, the wire angle θ is set in accordance with the lower and upper limits of the wire protrusion length. Generally, the wire protrusion length is set to be between 15 mm and 25 mm. If the wire angle θ is less than 3°, the wire protrusion length will be greater than 25 mm. If the wire angle is greater than 6°, the wire protrusion length will be less than 15 mm. Therefore, the wire angle θ is set to be between 3° and 6°.
[0064] <Regarding the appearance of the weld bead> The following describes the changes in the appearance of the weld bead when arc welding is performed with different welding currents.
[0065] In the example shown in Figure 12, the wire spacing x was set to 0.6 mm. With a wire spacing of 0.6 mm, when the welding current E was set to 300 A as shown in Figure 12, the bead width W of the weld bead 51 was 11.6 mm.
[0066] On the other hand, when the wire spacing x was 0.6 mm and the welding current E was set to 325 A, the bead width W of the weld bead 51 was 14.5 mm.
[0067] In this way, by adjusting the welding current E without changing the wire spacing x, the outer diameter of the bridge droplet 15 formed by the bridging of the first wire 10 and the second wire 20 can be changed, without having to replace the tip 35, and the base material 50 can be welded with an appropriate bead width W.
[0068] Next, in the example shown in Figure 13, we will consider the case where the wire spacing x is changed while the welding current E is set to approximately the same value.
[0069] In the left diagram of Figure 13, the welding current E is 374A and the wire spacing x is 0.6mm. In the right diagram of Figure 13, the welding current E is 379A and the wire spacing x is 1.2mm. The penetration depth P of the weld bead is 4.98mm when the wire spacing x is 0.6mm and 5.01mm when the wire spacing x is 1.2mm, indicating equivalent penetration depth.
[0070] On the other hand, the bead width W is 15.12 mm when the wire spacing x is 0.6 mm, and 17.32 mm when the wire spacing x is 1.2 mm.
[0071] Thus, according to the arc welding apparatus 1 of this embodiment, when arc welding is performed with a larger wire spacing x while keeping the welding current E the same, a wide weld bead can be obtained with the same penetration depth. [Industrial applicability]
[0072] As described above, the present invention offers a highly practical effect: the ability to change the outer diameter of bridged droplets formed by the bridging of the first and second wires without having to replace the tip. Therefore, it is extremely useful and has high industrial applicability. [Explanation of Symbols]
[0073] 1. Arc welding equipment 10. First wire 16 Arc 20. Second wire 30 Welding Torches 35 chips 36 First insertion hole 37 Second insertion hole 40 Wire feeding section 50 Base material
Claims
1. A wire feeding unit that feeds the first and second wires, which are consumable electrodes, toward the base material, The welding torch comprises the first wire and the second wire, and a welding torch that generates an arc between the first wire and the base material to weld the base material, The welding torch has a tip formed with a first insertion hole through which the first wire is inserted, and a second insertion hole located away from the first insertion hole through which the second wire is inserted. The first insertion hole and the second insertion hole extend in a direction in which the distance between them decreases as they move toward the tip of the chip. The tips of the first wire and the second wire protruding from the tip are arranged at a predetermined distance apart. Arc welding equipment.
2. In the arc welding apparatus according to claim 1, The protrusion lengths of the first wire and the second wire from the tip are 3 mm or more and 20 mm or less. The wire angle between the first wire and the second wire is 3° or more and 6° or less. Arc welding equipment.
3. A chip that supplies power to a first wire and a second wire, which are consumable electrodes, The chip is formed with a first insertion hole through which the first wire is inserted, and a second insertion hole located away from the first insertion hole through which the second wire is inserted. The first insertion hole and the second insertion hole extend in a direction in which the distance between them decreases as they move toward the tip of the chip. Tip.
4. The steps include feeding the first and second wires, which are consumable electrodes, from the tip toward the base material, The method includes the step of changing the wire spacing at the tips of the first wire and the second wire according to the protrusion length of the first wire and the second wire from the tip. Arc welding method.
5. In the arc welding method of claim 4, In the step of changing the wire spacing, the wire spacing becomes smaller as the protrusion length increases. Arc welding method.