JPH0670989U - Jig for single-sided welding - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a single-sided welding jig capable of suppressing deformation of the tab portion without applying external force to the tab portion and reliably and effectively suppressing end cracking. A tab portion is provided at each end of welding lines of a pair of materials to be welded, and a single-sided welding jig has a recessed portion 2 to be fitted in a state in which the tab plates are combined together.
It has in the lower half part. A notch 3 is provided in the upper half of the jig body 1, and the tab plate portion is welded through the notch 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a single-sided welding jig for preventing terminal cracks that are likely to occur in single-sided welding such as single-sided submerged arc welding and single-sided gas shielded arc welding.

[0002]

[Prior art]

 In single-sided submerged arc welding, a pair of plates to be welded are usually placed with their end faces to be welded to each other, and a V-shaped groove is formed on the welded face, and submerged only from the face where the groove is open. Weld both plates by arc welding. In this case, there is a problem that vertical cracks are likely to occur at the end of the weld line. It is speculated that this end crack is caused by the rotational deformation that occurs when the restraint at the end is released by the passage of the arc or becomes extremely weak. That is, in high heat input welding, thermal stress is applied to the end of the steel plate, the steel plate at the end is deformed, and the tensile stress at this time causes cracks in the weld metal.

Therefore, conventionally, a method for preventing terminal cracks in which a pressing force in the orthogonal direction is applied to the welding line in the plane of the plate to be welded from the outside by fluid pressure near the terminal end of the welding line of the plate to be welded. Has been proposed (Japanese Patent Publication No. 53-1215).

FIG. 8 is a schematic diagram showing this conventional method for preventing termination cracking. A tab plate 23 is provided at the end of the welding line 22 of each pair of plates 20 to be welded, and a pair of tab plates 23 is sandwiched by a pressing mechanism 24 provided on the restraining jig 25, and the tab plate 23 is pressed by a pressing mechanism. It is pressed by 24 in a direction orthogonal to the welding line 22. This prevents deformation of the plate 20 during arc welding and prevents terminal cracking. The press mechanism 24 normally gives a mechanical restraining force by a hydraulic jack or the like.

[0005]

[Problems to be solved by the device]

 However, in this conventional welding method for preventing terminal cracking, the tab plate 23 is mechanically constrained by applying an external force to the tab plate 23 with a hydraulic jack or the like. In some cases, the tensile stress generated in the weld metal part may be larger than the limit cracking stress in the weld metal part, and cracking occurs. Further, since the position of the tab plate to which the external force is applied is likely to change, it is not possible to effectively suppress the occurrence of cracks. Furthermore, the device becomes large because the tab plate is restrained by a mechanical external force. This situation also applies to single-sided gas shielded arc welding, and is a problem for general single-sided welding.

The present invention has been made in view of the above problems, and it is possible to suppress the deformation of the tab portion without applying an external force to the tab portion and reliably and effectively suppress the terminal crack. It is an object of the present invention to provide a jig for single-sided welding.

[0007]

[Means for Solving the Problems]

 The jig for single-sided welding according to the present invention is characterized by having a recess for fitting a pair of tabs respectively provided at the ends of the welding lines of a pair of materials to be welded together. To do.

Further, the present invention is characterized in that, when one tab portion is provided at the terminal end portion of the welding line in the pair of materials to be welded, it has a concave portion into which the tab portion is fitted.

[0009]

[Action]

 In the present invention, a pair of tab portions are combined or one tab portion fixed to both the pair of materials to be welded is fitted into the recess of the welding jig. As a result, even if the material to be welded is deformed by arc heat during arc welding, the tab portion is restrained by the jig and is not deformed, and terminal cracking of the weld metal portion is prevented. In this case, a restraining force acts on the tab portion from the jig substantially uniformly, and almost the same force acts on the tab portion, so that cracking or deformation of the tab portion is also prevented. Further, the present invention is particularly effective for the one having a large deformation of the joint end portion of the material to be welded, such as one-sided submerged arc welding of high heat input welding.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a single-sided welding jig according to an embodiment of the present invention, FIG. 2 (a) is a plan view of the same dam, and FIG. 2 (b) is a side view thereof. In the jig body 1 in the form of a plate, a concave portion 2 opening to the side 1 a side thereof is formed in the lower half of the jig body 1. The recess 2 is provided in the center of the side surface 1a of the jig body 1 where the recess 2 opens, and the rectangular notch 3 is formed at a position where the center of the recess 2 is aligned with the center in plan view. It is provided in the upper half of the ingredient body 1. The notch 3 is connected to the recess 2, and the portion of the notch 3 is hollowed out in the thickness direction in plan view.

As an example of the dimensions of the jig body 1, the width of the side surface 1a is 380 mm, the height is 50 mm, and the depth in plan view is 350 mm. The recess 2 has a width of 240 mm, a height of 30 mm and a depth of 270 mm, and the notch 3 has a width of 80 mm, a height of 20 mm and a depth of 200 mm.

In the single-sided welding jig configured as described above, as shown in FIG. 8, the tab plates 23 are fixed to the end portions of the welding lines 22 of the pair of welded plates 20, respectively. The 20 are butted against each other and the tab plate 23 is assembled. Then, the jig shown in FIGS. 1 and 2 is mounted on the pair of tab plates 23, and the tab plate 23 is fitted into the recess 2 of the jig. That is, the tab plate 23 is fitted into the recess 2 of the jig.

FIG. 7 shows a pair of welded plates 20 to which one tab plate 23 is welded and fixed to the ends of the welding lines of the welded plates 20. In this way, when the tab plate 23 is provided commonly to both the welded plates 20, the one tab plate 23 may be fitted by the recess 2 of the jig.

Accordingly, even if the tab plate 23 is deformed by heat during the submerged arc welding, the deformation is prevented by the restraint of the jig, so that the generation of the crack at the terminal end is prevented. The arc is moved along the welding line 22 and, after reaching the terminal end, the electrode is advanced to the tab plate 23, and the welding metal is also placed on the tab plate 23 to stop the welding. In this case, when the tab plate 23 is welded, since the notch 3 is provided in the jig, the jig does not obstruct the movement of the electrode and the arc. In this embodiment, since the tab plate 23 is restrained from deforming by restraining the position of the tab plate 23, unlike the case where the tab plate 23 is restrained by applying a mechanical pressing force, the tab plate 23 has a uniform force. It is possible to prevent the deformation of the.

Next, a second embodiment of the present invention will be described with reference to FIG. 3A is a plan view of this embodiment, and FIG. 3B is a side view thereof. In the tab fitting jig 10 of this embodiment, the screw 6 is provided in the side of the jig 10 so that the tip of the screw 6 projects from one side surface of the recess 2 into the recess 2. The base portion 4 is provided on the side surface opposite to this side surface. The tab portion 13 is sandwiched between the base portion 4 and the tip of the screw 6, and the screw 6 is tightened to fix the jig to the tab portion 13. When removing this jig, it can be easily removed by loosening the screw 5. In the present embodiment, even if there is a slight gap (play) between the concave portion 2 and the tab portion 13, the fastening with the screw 5 does not hinder the fixing of the tab portion. Therefore, the processing accuracy of the recess may be low, and the manufacturing cost thereof can be reduced. As shown in FIG. 3, the screw 6 is arranged on the opening side of the recess 2. This is because even if the tab plate 23 has a low processing accuracy, by restraining the tab plate 23 as close as possible to the base material (the plate 20 to be welded), its deformation can be prevented easily. is there.

FIG. 4 is a diagram showing a third embodiment of the present invention, FIG. 4 (a) is a plan view thereof, and FIG. 4 (b) is a side view thereof. In the present embodiment, the two screws 6 are screwed into the screw holes 5 provided in the jig body 11 so that the tip ends of the recesses 2 are exposed, and one of the two screws 6 is Is arranged on the opening side of the recess 2 and the other is arranged on the inner side of the recess 2. Further, a pair of pedestals 4a, 4b is arranged on the facing surface so as to face each screw 6. In this manner, each pair of screws 6 and the base 4a. By providing 4b, the screwing length of the screw 6 can be adjusted even when the side surface of the tab plate 23 is not parallel to the side surface of the recessed portion 2, that is, when the tab plate 23 is tilted into the jig. By doing so, the side surface of the tab plate 23 can be tightly fixed by the two screws 6. Therefore, in the case of the present embodiment, the tab plate 23 can be restrained with a uniform force as compared with the embodiment of FIG.

FIG. 5 is a view showing a fourth embodiment of the present invention, FIG. 5 (a) is a plan view thereof, and FIG. 5 (b) is a side view thereof. In this embodiment, a recess 2a is provided in the center of the jig body 12 in the height direction, a notch 3a is formed above the recess 2a, and a notch 3b is formed below the recess 2a. In this embodiment, the jig body 12 is horizontally moved toward the plate 20 to be welded, and the jig is engaged with the tab plate 23 by inserting the tab plate 23 into the recess 2a.

FIG. 6 is a view showing a fifth embodiment of the present invention, FIG. 6 (a) is a plan view thereof, FIG. 6 (b) is a side view thereof, and FIG. 6 (c) is a front view thereof. is there. In the jig 14 of this embodiment, the facing surface of the concave portion 2b is inclined, and the jig 14 is mounted by inserting the jig 14 horizontally with respect to the tab plate 23 as in the embodiment of FIG. It Further, the jig 14 of the present embodiment is configured such that the lower half portion can be removed and the lower half portion can be screwed.

That is, the lower member of the pair of parallel portions of the upper member 7 which is U-shaped in plan view is cut off, and the pair of plate members 8 having a trapezoidal cross section has the upper surface of the upper member 7. The notch 7 is aligned with the lower surface of the upper member 7 and is fixed to the upper member 7 with a screw 9. As a result, the pair of plate members 8 form concave portions 2b whose opposing surfaces are inclined with respect to each other. This embodiment can be used by adjusting the screwing length of the screw 9 even when the thickness of the tab plate 23 changes, or when the accuracy is poor, and is highly versatile.

The present invention is not limited to the above embodiment, but various modifications can be made. In particular, one-sided welding can be applied to various welding methods such as gas shield arc welding as well as submerged arc welding. Also, the tab plate is not limited to a combination of a pair of tab plates, and even when only one tab plate is used, the present invention has the same excellent effect.

[0022]

[Effect of device]

 As described above, according to the present invention, the position of the tab portion can be restricted only by fitting the recessed portion into the tab portion and mounting the one-sided welding jig. It is possible to prevent the occurrence of end cracks. Further, since the tab portion is restrained by simply fitting the concave portion of the jig without applying a mechanical external force to the tab portion, it can be carried out extremely easily and the apparatus does not become large.

[Brief description of drawings]

FIG. 1 is a perspective view showing a jig according to a first embodiment of the present invention.

2A is a plan view of the same, and FIG. 2B is a side view thereof.

3A is a plan view showing a jig according to a second embodiment of the present invention, and FIG. 3B is a side view thereof.

FIG. 4A is a plan view showing a jig according to a third embodiment of the present invention, and FIG. 4B is a side view thereof.

5A is a plan view showing a jig according to a fourth embodiment of the present invention, and FIG. 5B is a side view thereof.

6A is a plan view showing a jig according to a fifth embodiment of the present invention, and FIG. 6B is a side view thereof.

FIG. 7 is a plan view showing a single-sided welding method using one tab plate.

FIG. 8 is a plan view showing a conventional termination crack prevention method.

[Explanation of symbols]

 1, 10, 11, 12, 14; jigs 2, 2a, 2b, recesses 3, 3a, 3b; notches 4, 4a, 4b; base 5; screw holes 6, 9; screws 7; upper member 8; plate Member 20; Plate to be welded 22; Welding line 23; Tab plate 24; Press mechanism 25; Restraint jig

Claims (3)

[Scope of utility model registration request] 1. A jig for single-sided welding, comprising: a recess to which a pair of tab portions respectively provided at the ends of a welding line in a pair of materials to be welded are fitted together. 2. A jig for single-sided welding, comprising a recess for fitting a tab portion provided at a terminal end of a welding line in a pair of materials to be welded. 3. The single-sided welding jig according to claim 1, further comprising a screw that projects into the recess and contacts a side surface of the tab portion.