JPS6234670A - Longitudinal warp preventing method in fillet welding by intermittent preceding welding - Google Patents

Abstract

PURPOSE:To prevent the generation of the longitudinal warp in the fillet welding without tacking by performing a preceding welding intermittently by the preceding welding torch prior to the main welding and by performing the main welding in the state of constraining a steel sheet and aggregate by the preceding welding thereof. CONSTITUTION:The pressure fitting mechanism and preceding torch 13 consisting of pressing rollers 6, 8 and pressure fitting roller 9 are provided at the inlet port side of the device and a steel steel 1 and vertical rib 2 are fed to the left part and subjected to the main welding with performing the preceding welding. Namely the vertical rib 2 is guided with its upright by a tripping roller 4 and pinch roller 5 and the steel sheet 1 is contacted to the vertical rib 2 with its becoming dished by the pressing rollers 6, 8 and press fitting roller 9 as well. A preceding welding 14 is performed intermittently from one side by the preceding welding torch 13 at this contact point. Thereafter it is fed to the outlet port pressing roller 12 in the state of giving a reverse deformation by a reverse warping roller 7 which is arranged at the lower part of the pressing roller 8 and the main welding 11 is performed by the welding torch 10 therebetween.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for attaching a plurality of aggregates to a steel plate by welding without temporary attachment, and is suitable for use in, for example, frame-type equipment for shipbuilding. .

<Conventional technology> The most common method for integrating a flat steel plate and a vertical frame is to attach the vertical frame to the steel plate in its normal state as a preliminary work, perform temporary welding, and then perform the actual welding. This is a method for correcting distortion. However, in this method, temporary attachment is performed as a preliminary work, which is time-consuming. For this reason, many methods have been developed to improve efficiency by performing main welding without tack welding.

The apparatus devised at this institute for carrying out the method is shown in FIGS. 4-7. As shown in the figure, this apparatus welds the steel plate 1 and the vertical frame 2, to which only one end has been tacked 3, while feeding them in the direction of the arrow in the figure. That is, as shown in FIG. 5, this device includes anti-falling rollers 4 and pinch rollers 5 on the entrance side that guide the vertical rib 2 without tacking to the normal position in an upright position from both the left and right sides. In addition, as shown in FIG. 6, two press rollers 6 located on the left and right sides of the vertical frame 2 and a reverse strain roller 7 that push up the steel plate 1 from the lower surface with a required force are provided. , to give the steel plate 1 a deformation opposite to the angular deformation that occurs after welding. Furthermore, this device has a presser roller 8 on the top surface of the steel plate 1 on the exit side.
are arranged, and a pressure roller 9 is arranged between the presser rollers 6.8 to push up from the lower surface of the steel plate, so that the steel plate 1 is bent upward and pressed against the aggregate 2. While maintaining crimping and reverse deformation in this way, connect two electrodes from each side of the aggregate.
Main welding 11 is performed using a welding torch 10 with a total of four electrodes. This device has made it possible to improve the efficiency of installation work, eliminate temporary attachment, and prevent corner deformation.

<Problems to be Solved by the Invention> The conventional apparatus shown in Figs. 4 to 7 has the above-mentioned advantages and can perform fillet welding of aggregate to steel plates without tack welding. It has become clear that distortion often increases. In other words, generally when welding after tacking, the steel plate and aggregate behave as one, and the neutral axis (N,
Depending on the relative positional relationship between A) and the welded part, the tendency of upward warpage in Fig. 8 and downward warpage in Fig. 9 is shown. These are all caused by the fact that the shrinkage during cooling after welding is greater than the elongation due to thermal expansion during welding. On the other hand, when main welding is performed without tack welding, both the steel plate and the vertical frame behave separately.

That is, as shown in FIGS. 10 and 11, the vertical ribs 2 extend separately around their neutral axes (L, N, A), and the steel plate 1 extends separately around their neutral axes (P, N, A). After welding, they become one piece and then shrink. In both figures, solid line arrows 21 and 22 indicate the steel plate 1. The elongation of the longitudinal rib 2 during welding is shown, and the dashed arrows 23 and 24 each indicate the shrinkage of the steel plate 1° after welding of the longitudinal rib 2. As is clear from these, during welding, the steel plate 1 and the vertical rib 2 extend as shown by arrows 21 and 22, but
The vertical rib 2 extends more than the steel plate 22 due to the heat capacity. After welding is completed, they try to shrink as shown by arrows 23 and 24, but since they are integrated, the amount is the same. As a result, as shown in Fig. 11, the residual deformation due to elongation and contraction is shown by e and e, both the steel plate and the aggregate are left with a large downward warping deformation, and a larger strain than that of the temporarily attached one is generated.

In view of the above-mentioned prior art, it is an object of the present invention to provide a method that can prevent the occurrence of aX, that is, downward warpage, in fillet welding without tack welding.

Means for Solving the Problems〉 The structure of the present invention to achieve the above object: A device for performing fillet welding of aggregate on a steel plate without tack welding, a crimping mechanism and a pre-welding torch are provided on the inlet side of the device. When performing fillet welding using a device incorporating the above, it is recommended that prior welding be performed intermittently with the preceding welding torch before the main welding, and that the main welding be performed with the steel plate and aggregate restrained by this preceding welding. This is a characteristic feature. Here, preliminary welding is different from tack welding that is normally performed for assembly, and is welding that is performed so that the influence of heat is restrained between the steel plate and the vertical frame to prevent residual strain, and is the actual welding. This can be done with a welding torch built into the equipment that performs the process.

When performing main welding after tack welding, generally the neutral axes N and A are located above the weld line as shown in Fig. 8, and there is a tendency for upward warping, but in the method of the present invention, Since preliminary welding is performed intermittently before the main welding, by adjusting the pitch of the preliminary welding, the downward curvature without tack welding is offset, and the neutral axis is maintained straight.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Incidentally, the same parts as those in the prior art described above are given the same numbers and the description thereof will be omitted.

1 to 3 show the apparatus used in the method of the present invention. The device feeds the steel plate 1 and the vertical rib 2, which have been tacked 3 only on one end, in the direction of the arrow in the figure, while the
This is a device for fillet welding the vertical ribs 2 and 2. That is, on the inlet side of this device, there is a presser roller 6.8 as shown in FIG.
A pressure bonding mechanism consisting of a pressure bonding roller 9 and a pressure bonding roller 9 is provided, and as shown in FIG. 2, a preceding welding torch 13 is provided above the pressure bonding roller 9 on one side thereof. The preceding welding torch 13 is designed to be capable of intermittent welding, and is preferably a torch that does not generate spatter or slag, such as a clean mag. In addition, 12 in the figure is an exit presser roller, and the other configurations are the same as those shown in FIGS. 4 to 7.

Therefore, the flange plate 1 and the vertical ribs 2, which are sent to the left as shown by the arrow in FIG. 1, are welded in advance while being welded in the following manner. That is, the vertical ribs 2 are guided upright by the anti-falling rollers 4 and the pinch rollers 5, and the steel plate 1 is bent upward and pressed against the vertical ribs 2 by the press rollers 6.8 and the pressure rollers 9.

At this crimping point, the preceding welding torch 13 performs preliminary welding 14 intermittently from one side. Thereafter, the sheet is reversely deformed by a reverse strain roller 7 disposed below the presser roller 8 and sent to the outlet presser roller 12, where a welding torch 10 performs main welding 11 therebetween. In addition, the feeding force is the reverse strain roller 7.
It is also given by

As described above, in this embodiment, the steel plate 1 and the vertical rib 2 are crimped by the crimping mechanism consisting of the presser roller 6° 8 and the crimping roller 9, and the main welding is carried out after the welding is performed intermittently in advance. The steel plate 1 and the vertical frame 2 do not behave separately due to thermal effects during welding, and no residual strain remains.

<Effects of the Invention> As specifically explained above based on the examples, the method of the present invention corrects vertical distortion (warpage), eliminates the work of removing distortion, and reduces the number of man-hours. Quality can be ensured. Furthermore, since a device that can perform preliminary welding and main welding is used, tack welding is not necessary, which is efficient.

Moreover, by adjusting the pitch of the preceding welding, it is also possible to achieve welding without distortion.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus used in the method of the present invention, and FIGS. 2 and 3 are lines DD and E in FIG. 1, respectively.
4 is a schematic diagram showing an apparatus for performing fillet welding without tack welding according to the prior art, and FIGS. 5, 6, and 7 are C-C in FIG. 4, respectively. line, B-B line, A-Ai sectional view, FIGS. 8 and 9 are perspective views showing upward curvature and downward curvature, respectively,
FIGS. 10 and 11 are a perspective view and a side view, respectively, showing longitudinal strain when main welding is performed without tack welding. In the drawing, 1 is a steel plate, 2 is a vertical frame, 3 is a tack weld, 4 is a fall prevention roller, 5 is a pinch roller, 6.8 is a press roller, 7 is a reverse strain roller, 10 is a welding torch, 11 is a 12 is the exit presser roller) 13 is the preliminary welding torch, 14 is the preliminary welding, N, A, L, N, A, P, N, A are the middle and vertical axes.

Claims (1)

[Claims] For equipment that performs fillet welding without temporary attachment of aggregate to steel plates,
When performing fillet welding using a device that incorporates a crimping mechanism and a preceding welding torch on the inlet side, preliminary welding is performed intermittently by the preceding welding torch prior to main welding, and this preliminary welding separates the steel plate and aggregate. A method for preventing longitudinal strain in fillet welding by intermittent pre-welding, which is characterized by performing main welding while restraining the fillet weld.