JPH0232076B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a plug welding device. Conventionally, arc spot welding has been widely used to join plates and frames, or plates together in the assembly of vehicles, etc., but this arc spot welding method can be used to join the bottom parts without creating a special groove. This is a method of welding by placing the upper base material 2 on the side base material 1 and bringing them into surface contact, and by penetrating and melting the upper base material 2. Therefore, the longitudinal cross-sectional shape of the welded portion is as shown in FIG. By the way, in this welding method, as is clear from the penetration shape described above, if the surface condition of the base metal changes or the set-up gap between the base metals changes, the joint surface width Wi There is a drawback that the bonding surface width Wi and the penetration depth d vary greatly, making it difficult to always ensure a predetermined amount of the joint surface width Wi and penetration depth d. In particular, due to the above and the melting ability of this method, there is a limit to the thickness of the upper base material 1 that can be used, which is a major drawback. Furthermore, depending on the welding conditions, welding defects such as crater cracks may occur. Therefore, when the thickness of the upper base material becomes large, as shown in FIG. A so-called plug welding method is employed in which a tip 4 is formed and this portion is laminated and welded by semi-automatic welding or manual welding. However, this welding method has problems such as the fact that the groove processing requires a great deal of effort and that welding defects such as poor penetration and poor fusion occur at a considerable frequency at the bottom of the groove. Furthermore, since welding is performed with the arc stationary, the final solidification point is trapped within the bead at the end of welding, which may result in crater cracking. As mentioned above, in the conventional welding method,
When using the arc pot welding method, work efficiency is good because there is no need for beveling, etc., but
If the thickness of the upper base material becomes large, there is a drawback that it becomes impossible to secure the joint surface width Wi required for design strength. Although the bonding surface width Wi can be secured to some extent, it is necessary to perform bevel processing, which has the disadvantage that this processing requires a great deal of effort and leads to a decrease in work efficiency. This invention was made in view of the above, and its purpose is to be able to sufficiently secure the joint surface width Wi and penetration depth d necessary for the design strength, and to eliminate the need for beveling. An object of the present invention is to provide a plug welding device capable of carrying out a highly efficient plug welding method. The plug welding method of the present invention, which achieves the above object, is a plug welding method in which a circular hole is bored in an upper base material placed on a lower base material, and a welding torch is moved along the circular hole. , the welding torch is attached to a swing arm, the swing arm is movably and rotatably supported in the axial direction by a swing support, and one end of the swing arm is pivoted; This method is characterized by causing the welding torch to move in a circular motion. The plug welding device of the present invention used to carry out the above method includes a main shaft rotationally driven by a drive source such as a motor, a rotating body attached to the main shaft, and a rotating body attached to the rotating body. a pivot pin that pivots around its axis as the main shaft rotates; a swing arm that has one end pivoted to the pivot pin; and a swing arm that is movable in the axial direction and rotates. A welding torch which is attached to the swing arm and rotated substantially parallel to the pivot pin by the pivot pin. becomes. Next, specific embodiments of the plug welding apparatus of the present invention will be described in detail with reference to the drawings. First, as shown in FIG. 3, a circular hole 13 is bored in the upper base material 12 placed on the lower base material 11. In this case, the diameter 2r of the circular hole 13 is set equal to or slightly smaller than the predetermined joint surface width Wi, although it depends on the welding method and turning conditions. Note that, unlike the conventional method, beveling (chamfering) around the circular hole 13 is of course unnecessary. Then, the tip of the welding torch is rotated along the circular hole 13 by a torch rotation mechanism A, which will be described later, so as not to twist the wire feeding system. In this case, as shown in FIG.
degree) move inside. Further, at this time, the welding conditions are automatically changed so that the welding surface beat width Ws becomes a desirable dimension, that is, within a range of 1.5 to 2.0 times the predetermined joint surface width Wi. That is, as shown in Table 1, the plate thickness t of the upper base material 12
and the welding conditions S for the first layer according to the torch rotation speed R.
1. Each welding condition is determined in advance, such as welding condition S2 for lamination and welding condition S3 for finishing,
These are programmed so that welding conditions can be changed step by step during welding.

[Table] As described above, a welded portion as shown in FIG. 4a is formed. Next, the torch rotation mechanism A for rotating the welding torch as described above will be explained based on FIGS. 5a and 5b. In the figure, reference numeral 14 denotes a drive source such as a motor, and a disk-shaped rotating body 16 is attached to a main shaft 15 that is rotated by the drive source 14. A pivot pin 17 is attached to a position eccentric from the rotation center of the rotating body 16, and the pivot pin 17 is moved by the rotation of the main shaft 15.
It is designed to be able to rotate around its axis. 1
Reference numeral 8 denotes an elongated swinging arm, and an elongated hole 19 is provided in the middle part of the swing arm.
The pin portion 20a of the rotating support body 20 is inserted therein. As a result, the swinging arm 18 is
0 to be movable in its axial direction and rotatably supported. In addition, the swing arm 18
One end is pivotally connected to the pivot pin 17, and a welding torch 21 is attached to the other end. In the device as described above, the drive source 14
When the main shaft 15 rotates, the pivot pin 17, that is, one end of the swing arm 18, pivots accordingly. On the other hand, since the intermediate portion of the swing arm 18 is supported by the swing support 20 as described above, the swing arm 18 is the other end,
That is, the welding torch 21 turns in the opposite direction to the above-mentioned turning method. In addition, in the above device, the swing support body 20 that supports the swing arm 18 may have the shape shown in the figure, or the swing support body 20 that supports the swing arm 18.
8 can be moved in the axial direction and rotatably supported. For example, in practice, a plurality of ball rolling R
A spline and linear bearing is used in which a groove is provided and a large diameter ball rolls in this raceway groove, making an infinite linear motion. Further, the swing arm 18 does not support its intermediate portion as described above, but supports its free end rotatably and movably in the axial direction, and the welding torch 21 is attached to the intermediate portion. Sometimes I do. Next, as described above, using the torch rotation mechanism A, an apparatus for automatically and continuously welding a welding part having a plurality of circular holes 13...13 arranged in two rows as shown in FIG. I will explain about it. The device is shown in FIGS. 7a and 7b, in which the torch rotation mechanism A is mounted on a gate-shaped self-propelled frame 22, and a rail stand 23 is installed horizontally on the top of the self-propelled frame 22. Upward horizontal movement linear head 2
4, and further provided with an elevating linear head 25 which is driven in the horizontal direction by this linear head 24, and the torch rotation mechanism A is attached to this elevating linear head 25. As a result, the torch rotation mechanism A, on the self-propelled frame 22,
It is supported so that its position can be adjusted horizontally and vertically. Then, as shown in FIG. 8, the object to be welded 26 is placed inside the self-propelled frame, and the gate-shaped self-propelled frame 22 is moved along the object to be welded 26 while detecting the preceding circular hole 13. , the circular holes 13 arranged in two rows are welded simultaneously and continuously. Specific welding test results using the above welding method will be explained below. In addition, in the following explanation, I is arc current A, V is arc voltage V, T is arc time (seconds), R is rotation speed (rotations/minute), and Q
indicates the shielding gas flow rate (/min) and gas type, and the thickness of the upper base material used is
12mm, the diameter of the circular hole is 18-20mm. Example 1 The diameter of the circular hole is 18 mm, and the welding wire is 1.2 mm in diameter.
I used the one from (1) 1st rotation: I = 350 V = 38 T = 10 R = 18 Q = 40 (CO ₂ ) (2) 2nd rotation: I = 250 V = 28 T = 10 R = 18 Q = 40 (CO ₂ ) Example 2 The diameter of the circular hole is 18 mm, and the diameter of the welding wire is 1.2 mm.
I used the one from (1) 1st rotation: I=350 V=36 T=8 R=18 Q=40 (CO ₂ ) (2) 2nd rotation: I=250 V=30 T=8 R=18 Q=40 (CO ₂ ) Example 3 The diameter of the circular hole is 20 mm, and the diameter of the welding wire is 1.2 mm.
I used the one from (1) 1st rotation: I = 350 V = 36 T = 10 R = 18 Q = 40 (CO ₂ ) (2) 2nd rotation: I = 200 V = 30 T = 10 R = 18 Q = 40 (CO ₂ ) Example 4 The diameter of the circular hole is 20 mm, and the diameter of the welding wire is 1.2 mm.
I used the one from (1) 1st rotation: I = 350 V = 38 T = 10 R = 18 Q = 40 (CO ₂ ) (2) 2nd rotation: I = 280 V = 28 T = 10 R = 18 Q = 40 (CO ₂ ) Example 5 The diameter of the circular hole is 20 mm, and the diameter of the welding wire is 1.2 mm.
I used the one from (1) 1st rotation: I=350 V=36 T=10 R=18 Q=40 (80%Ar+20%CO ₂ ) (2) 2nd rotation: I=280 V=34 T=10 R=18 Q = 40 (80% Ar + 20% CO ₂ ) Example 6 The diameter of the circular hole is 20 mm, and the diameter of the welding wire is 1.2 mm.
I used the one from (1) 1st rotation: I=350 V=38 T=10 R=18 Q=40 (80%Ar+20%CO ₂ ) (2) 2nd rotation: I=280 V=34 T=10 R=18 Q = 40 (80% Ar + 20% CO ₂ ) The penetration shapes of the welds obtained under the welding conditions of Examples 1 to 6 above are shown in Figures 9 a to f. The method makes it possible to obtain very good welding results. The plug welding device of the present invention is configured as described above, and therefore, according to the present invention, it is possible to sufficiently secure the joint surface width and penetration depth necessary for the design, so that the joint Reliability can be greatly improved, and since there is no need to perform bevel processing, it is possible to significantly improve work efficiency. Moreover, according to the above device, the welding torch is rotated approximately parallel to the circumferential wall of the circular hole, so even if the thickness of the base material increases, it can be handled simply by changing the lifting distance of the torch. Therefore, the operability is improved compared to the conventional method. It should be noted that the plug welding apparatus of the present invention is not limited to the above-mentioned embodiments, but it is obvious that it can be implemented with various modifications within the scope of its purpose.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the penetration shape in conventional arc spot welding, Fig. 2 is an explanatory diagram of the groove shape used in the conventional welding method, and Fig. 3 is an explanatory diagram of the welded part used in the plug welding method of the present invention. Figure 4a is an explanatory diagram of the penetration shape obtained by the plug welding method of the present invention, b is an explanatory diagram showing the aiming position of the welding torch in this case, and Figure 5 is the principle of the plug welding method of the present invention. FIG. 6 is an explanatory diagram showing an example of a workpiece to be welded; a is a plan view thereof; b is a front view thereof; FIG. 6 is an explanatory diagram showing an example of an object to be welded; FIGS. FIG. 9 is a diagram showing an example of an automatic welding device, in which a is a front view thereof, b is a side view thereof, FIG. 8 is an explanatory diagram of a state in which welding is performed using the above device, and FIG.
Figures a to f are diagrams showing the metal structure of a welded part obtained by the method of the present invention. 11...Lower base material, 12...Upper base material, 13...
... circular hole, 14 ... drive source, 15 ... main shaft, 16 ...
...Rotating body, 17... Pivoting pin, 18... Swinging arm, 20... Swivel support, 21... Welding torch.

Claims (1)

[Claims] 1. A main shaft that is rotationally driven by a drive source such as a motor, a rotating body attached to this main shaft, and a rotating body that is attached to this rotating body and rotates around its axis by rotation of the main shaft. a pivot pin, a swing arm whose one end is pivotally connected to the pivot pin, a swing support that supports the swing arm so as to be movable in its axial direction and rotatable; A plug welding device comprising a welding torch attached to the pivot pin and rotationally driven substantially parallel to the pivot pin by rotation of the pivot pin.