JPS6030575A - Method and device for plug welding - Google Patents

Abstract

PURPOSE:To improve reliability of a joint and the efficiency of a welding operation by moving circularly a torch by means of an oscillating arm supported to a swiveling support in the stage of moving the torch along the circular hole of an upper base metal placed on a base metal. CONSTITUTION:A circular hole 13 is punched to an upper base metal 12 placed on a lower base metal 11 and the tip of a welding torch 21 is moved along the hole 13 to perform plug welding. A mechanism A for rotating the torch which applies circular motion to the torch 21 attached to the other end of an oscillating arm 18 supported in the central part by a rotary support 20 by turning the one end of aid arm by a pivotal pin 17 of a turning body 16 fitted 15 pivotally to a driving source 14. Welding is accomplished repeatedly by setting programmatically the welding conditions for the root pass, building-up and finishing according to the thickness of the material 12. The joint surface width and penetration depth necessary for design are thus substantially assured and the working efficiency is improved without requiring intricate edge preparation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plug welding method and a plug welding apparatus used to carry out the method.

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 does not require any special grooves. This is a method of welding by placing the upper base material 2 on the lower 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 above-mentioned welding shape, the surface condition of the base material changes,
Alternatively, if the centamp gap between the base materials changes, the joint surface width Wi, penetration depth d, etc. will change significantly, so it is necessary to always ensure a predetermined amount of joint surface clearance and penetration depth d. The disadvantage is that it is difficult to In particular, due to the above and the melting capabilities of this method, the upper base material 1. ) Plate thickness 6. Having a limited door is also 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. forming the tip 4,
This part is laminated by semi-automatic welding or manual welding, which is the so-called plug welding method. 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 conventional welding construction methods, when the arc spot welding method is adopted, work efficiency is good because groove processing etc. are not required, but when the thickness of the upper base material becomes large, There is a drawback that it is impossible to secure the joint surface width Wi required for design strength, and when the above-mentioned plug welding method is adopted, the specified joint surface @14
Although it is possible to secure i to a certain extent, it is necessary to perform beveling, which has the drawback that this processing requires a great deal of effort, leading 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 clearance and penetration depth d necessary for design strength, and to improve work efficiency since beveling is not required. An object of the present invention is to provide an excellent plug welding method and a plug welding device used for carrying out the 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 swinging arm, the swinging arm is movably and rotatably supported in the axial direction by a swinging support, and welding is carried out by swinging one end of the swinging arm. It is characterized by a circular motion of the torch.

Furthermore, the plug welding device of the present invention used to carry out the above method includes:
a main shaft rotatably driven by a drive source such as a motor; a rotating body attached to the main shaft; a pivot pin attached to the rotating body and pivoting about its axis as the main shaft rotates; a swinging arm whose one end is pivotally connected to a pivot pin; a swinging support that is movable in the axial direction and rotatably supports the swinging arm; and a swinging support that is attached to the swinging arm and The welding torch is rotatably driven by the rotation of the pivot pin.

Next, specific embodiments of the plug welding method and 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, circular hole 1
The diameter 2r of No. 3 depends on the welding method and construction conditions, but it should be equal to or slightly smaller than the specified joint surface. 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. 4(b), the tip of the torch is moved a predetermined distance Tr (
Regardless of the diameter of the circular hole, move the inside (approximately 2.5 cm). Further, at this time, the welding conditions are automatically changed so that the welding surface bead 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, each welding is performed under welding conditions S1 for the first layer, welding conditions S2 for lamination, and welding conditions S3 for finishing according to the plate thickness of the upper base material 12 and the torch rotation speed R. The conditions are determined in advance and programmed so that the welding conditions can be changed step by step during welding.

Table 1 As described above, a welded portion as shown in FIG. 4(a) is formed.

Next, the torch rotation mechanism A for rotating the welding torch as described above will be explained based on FIGS. 5(a) and 5(b). In the figure, 14 is a drive source such as a motor, and a main shaft 15 rotated by this drive source 14 includes:
A disc-shaped rotating body 16 is attached. This rotating body 16
A pivot pin 17 is attached at a position eccentric from the center of rotation of the rotor, and the pivot pin 17 can be pivoted about its axis by the rotation of the main shaft 150.

Reference numeral 18 denotes an elongated swinging arm, and an elongated hole 19 is provided in the middle of the arm, into which the pin portion 20a of the swing support 20 is inserted. As a result,
The swing arm 18 is movable in its axial direction and rotatably supported by the swing support 20. One end of the swing arm 18 is pivotally connected to the pivot pin 17, and a welding torch 21 is attached to the other end. In the above-described device, when the main shaft 15 of the drive source 14 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 supported by the swing support 20 as described above.
As one end of the swing arm 18 pivots, the other end of the swing arm 18, that is, the welding torch 21, pivots in a direction opposite to the above-mentioned pivot direction. In addition, in the above device,
In addition to the shape shown in the drawings, the swing support 20 that supports the swing arm 18 can also use other means capable of supporting the swing arm 18 in a movable and rotatable manner in its axial direction, for example. Practically speaking, a spline and linear bearing is used in which a plurality of R grooves for ball rolling are provided on the outer diameter of the cylindrical shaft, and large-diameter balls roll in these raceway grooves to perform 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, using the torch rotation mechanism A as described above, the sixth
As shown in the figure, a plurality of circular holes 13 arranged in two rows...
・A device for automatically and continuously welding a welded portion having 13 points will be explained. The device is shown in FIGS. 7(a) and 7(b), in which the torch rotation mechanism A is mounted on a concave self-propelled frame 22, and a rail is installed horizontally on the top of the self-propelled frame 22. A horizontally movable linear head 24 is mounted on a table 23, and an elevating linear head 25 that is driven horizontally by the linear head 24 is provided, and the torch rotation mechanism A is attached to this elevating linear head 25. As a result, the torch rotation mechanism A is
It is supported on the self-propelled frame 22 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. At the same time, the circular holes 13 arranged in two rows are simultaneously and continuously welded.

Specific welding test results using the above welding method will be explained below. In the following explanation, ■ is the arc current (A), V is the arc voltage (■), T is the arc time (seconds), R is the rotation speed (7 minutes of rotation), and Q is the shielding gas flow rate (A/min). ) and the type of gas, respectively.
The thickness of the upper base material used was 12 Tsuru, and the diameter of the circular hole was 18~
It is 20mm.

The diameter of the circular hole was 1811 mm, and the welding wire was 1.2 mm in diameter.

(l) 1st rotation: I = 350 V = 38 T = 1O
R=18 'Q=40 (Co,) (2) 2nd rotation: I =250 V=28 T=1O
R=18 Q=40 (CO2) Actual difference side -''4 The diameter of the circular hole was 18 mm, and the welding wire used had a diameter of 1.21 mm.

(1) 1st rotation: I=350 V=36 T=8R=1
8 Q=40 (CO2) (2) 2nd rotation: I =250 V=30 T=8
R=18 Q=40 (CO2) 1 plate-■ The diameter of the circular hole was 20 mm, and the welding wire was 1.2 mm in diameter.

(l) 1st rotation: I = 350 V = 36 T = 1O
R=18 Q=40 (co2) (2) 2nd rotation: I =200 V=30 T=1O
R = 18 Q = 40 (CO2) Actual] 1.2 The diameter of the circular hole was 201, and the welding wire was 1.2 mm in diameter.

(1) 1st rotation: I = 350 V = 3B T = 10
R=18 Q=40 (CO2) (2) 2nd rotation: I =280 V=28 7=1O
R=18 Q=40 (CO2,) Example 1" Rainbow-1 The diameter of the circular hole was 200, and the welding wire used was one with a diameter of 1.2.

(1) 1st rotation: l-350 V=36 T=1OR=
18 Q=40(80%Ar+20%CO□)(2)2
Rotation: I = 280 V = 34 T = 1 OR = 18
Q=40 (80%Ar+20%C02) Real JL (Masu-
- The diameter of the circular hole was 20 mm, and the welding wire was 1.2 mm in diameter.

(l) 1st rotation: I = 350 V = 38 T = 10
R=18 Q=40 (80%Ar + 20%C0
2) (2) 2nd rotation: I = 280 V = 34 7 =
1OR=18 Q=40(80%Ar+20%CO,t
) The welded shapes of welded parts obtained under the welding conditions of Examples 1 to 6 above are shown in FIGS. 9(a) to 9(f), and as is clear from the figures, according to the method of the present invention, It is possible to obtain very good welding results.

The plug welding method and plug welding apparatus of the present invention are constructed 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 design. The reliability of the joint can be greatly improved, and since there is no need to perform beveling, the work efficiency can be significantly improved.

It should be noted that the plug welding method and plug welding apparatus of the present invention are not limited to the above-mentioned embodiments (it is obvious that they can be implemented with various modifications within the scope of the object thereof.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the welded shape in conventional arc spot welding, Fig. 2 is an explanatory diagram of the groove shape used in conventional plug welding, and Fig. 3 is an explanatory diagram of the welded part used in the plug welding method of the present invention. 4(a) is an explanatory diagram of the welded shape obtained by the plug welding method of the present invention, FIG. 4(b) is an explanatory diagram showing the aiming position of the welding torch in that case, and FIG.
The figures are explanatory drawings showing an example of the principle of the plug welding method of the present invention, in which (a) is a plan view thereof, (b) is a front view thereof, FIG. 6 is an explanatory drawing showing an example of the object to be welded, and FIG. Figures (a) and (b) are diagrams showing an example of an automatic welding device using the plug welding device of the present invention, in which (a) is a front view thereof, (b) is a surface view thereof, and
The figure is an explanatory diagram of a state in which welding is performed using the above-mentioned apparatus, and FIGS. 9(a) to 9(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... Pivot pin, 18... Swinging arm,
20... Rotating support body, 21... Welding torch. Figure 5 Figure 6

Claims (1)

[Claims] 1. A circular hole is bored in the upper base material placed on the lower base material,
This is a plug welding method in which a welding torch is moved along this circular hole, and the welding torch is attached to a swing arm, and the swing arm is movable in the axial direction and rotated by a swing support. A plug welding method characterized in that the welding torch is moved in a circular motion by pivoting one end of a swinging arm. 2. A main shaft rotationally driven by a drive source such as a motor;
A rotating body attached to the main shaft, a pivot pin attached to the rotating body and pivoting about its axis as the main shaft rotates, and a pivot whose one end is pivoted to the pivot pin. a movable arm, a pivoting support that is movable in the axial direction and rotatably supports the pivoting arm, and a welding torch that is attached to the pivoting arm and rotationally driven by pivoting of the pivot pin. A plug welding device comprising: