JPS6147637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for preventing welding distortion in edge joints of thin plate materials.

<Prior Art> It is known that when welding thin plate materials, distortion occurs in the entire material to be welded due to thermal contraction associated with welding. Of these shrinkage deformations, the transverse shrinkage that occurs perpendicular to the weld line is the most basic.
Significant longitudinal shrinkage occurs in the direction of the weld line. Particularly, as shown in FIG. 5, two thin plates 11 and 12 having an L-shaped cross section with a thickness of 5 mm or less are used to form left and right side portions 11a and 12a and upwardly projecting edge joint portions 11b and 12b. When applying edge joint welding to the upper edges of the edge joint portions 11b and 12b, this vertical shrinkage causes the edge joint portions 11b and 12b to
b, 12b are distorted in the height direction, thereby bending with the welded edge joint portions 11b, 12b inside.

Methods for correcting such welding distortions include heating the area after welding to cause thermal contraction, which generates tension and straightens the curve. Since this method may have adverse effects such as deterioration of the thin plate base material, it must be implemented with caution. Therefore, a method is used in which a reverse strain is applied by bending the welded material in advance in a direction opposite to the welding strain.

<Problems to be Solved by the Invention> By the way, in this method of applying reverse strain, even if it is attempted to apply reverse strain to the welded material in advance, it may be difficult to apply reverse strain depending on the welding shape. be.
In other words, when applying a strain that is mainly inverse to the welding strain on the plate, such as fillet welding when attaching ribs to a plate, there is no problem since the ribs are not deformed, but as shown in Figure 5. Thin plate material 11,
When welding the upper edges of the twelve edge joint portions 11b, 12b, there is a problem in that simply applying force causes lateral waviness in the edge joint portions 11b, 12b. In other words, in such edge joint welding, reverse strain against welding deformation must be taken in the height direction of the edge joint portions 11b and 12b, but in this case, the edge joint portion 11
b, 12b in the height direction so that the edge joint portions 11b, 12b are on the outside, as shown in FIG. 7, the edge joint portions 11b,
The proximal end of 12b is compressed and wrinkles are generated in that part, and the wrinkles are continuous with the left and right side parts 11.
This causes the generation of wrinkles in the edges a and 12a, and also leads to lateral waviness in the edge joint portions 11b and 12b. If these undulations are severe, not only will the product be defective in shape, but the welding line will meander, making it difficult for the welding torch to follow.

The present invention has been made in view of the above circumstances, and provides a thin plate material welding method that can easily apply reverse strain while preventing lateral waviness of the edge joint portion in edge joint welding of thin plate materials. It is an object of the present invention to provide a distortion prevention method and device.

<Means for Solving the Problems> The structure of the method for preventing welding distortion of thin plate materials according to the present invention to achieve this object is to extend two thin plate materials having an L-shaped cross section to the left and right sides and to the upper side. After pasting together to form an edge joint part, when edge welding the upper edge of the edge joint part, the left and right sides of the thin plate material to be welded are bonded to both upper and lower sides by thick plate material covering the entire surface thereof. The thin plate material is welded together with the thick plate material by preloading a strain in the direction opposite to the welding strain in the height direction of the edge joint portion. In addition, the structure of the thin plate material welding strain prevention device according to the present invention is such that two thin plate materials having an L-shaped cross section are pasted together to form left and right side portions and an upwardly projecting edge joint portion. a thick plate material consisting of a lower plate that covers the lower surface of the left and right side portions, and an upper plate that covers the upper surface of the left and right side portions and has a slit into which the edge joint portion is inserted; A hydraulic jack and a spacer that apply strain to the welded material in a direction opposite to the welding strain in the height direction of the edge joint portion while the left and right side portions of the material are clamped from both upper and lower surfaces; It is characterized by comprising a supporting arm, and a surface plate on which the thick plate material, hydraulic jack, arm, and spacer are placed.

<Function> The thick plate material clamps both the upper and lower sides of the left and right sides of the material to be welded, and in this state, reverse strain is applied to the thick plate material and both left and right sides as one body, so the left and right distortion caused by bending is caused by the clamping pressure of the thick plate material. Creases are prevented from forming on both sides, thereby restraining the edge joint portion and preventing wrinkles from forming at the edge joint portion. Therefore, a reverse strain is applied to the edge joint without causing lateral waviness in the edge joint portion.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a side view of an apparatus according to an embodiment of the present invention showing a state in which a reverse strain is applied to a thin plate, FIG. 2 is a side view in a state in which no reverse strain is applied, and FIG.
The figure is a plan view thereof, and FIG. 4 is an enlarged cross-sectional view of FIG. 2.

As shown in FIGS. 1 to 3, arm pedestals 14 are fixed to both ends of the upper surface of the surface plate 13, respectively.
An arm 17 is attached to the arm holder 14 via pins 15 and 16. The arm 17 has a base that fits into the arm holder 14 and a head that projects toward the other arm 17. When both pins 15 and 16 are inserted, they are fixed to the arm pedestal 14, and when one pin 16 is pulled out, the other pin 15 becomes the center. It is designed so that it can be rotated. A hydraulic jack 18 is attached to the head of the arm 17 so as to extend downward, and this hydraulic jack 18 applies a reverse strain to the thin plates 11 and 12, which are the materials to be welded.

On the other hand, the left and right side portions 11 of the thin plate materials 11 and 12
A thick plate material 19 is provided for clamping the parts a and 12a. The thick plate material 19 has left and right side parts 11a and 12a.
It consists of a lower plate 20 disposed below and an upper plate 21 disposed above it, the lower plate 20 and the upper plate 2.
1 has a width that covers the entire surface of the left and right side portions 11a and 12a, and the upper plate 21 has a width that covers the entire surface of the left and right side portions 11a and 12a, and the upper plate 21 has
As shown in the figure, a window-like slit 21a is opened through which the edge joint portions 11b and 12b projecting upward from the thin plates 11 and 12 pass. Therefore,
Two thin plate materials 1 having an L-shaped cross section as materials to be welded
1 and 12 are pasted together in a T-shape to form left and right side portions 11a, 12a and edge joint portions 11b, 12b, and then the edge joint portions 11b,
12b is inserted into the slit 21a, and its left and right side portions 11a and 12a are sandwiched between the lower plate 20 and the upper plate 21 from both the upper and lower sides in a sandwich-like manner. Incidentally, the slit 21a of the upper plate 21 is formed by the upper plate 21 at the edge joint portion 11b,
In order to be able to press the portion near the proximal end of 12b, the width is formed as narrow as possible within the range that allows the edge joint portions 11b and 12b to pass through.

In addition, the thin plate materials 11 and 12 are placed on the lower plate 20,
Further, an upper plate 21 is placed on top of the thin plate materials 11 and 12 so that they can be transported together.
A hanging piece 22 is attached for regulating the upper plate 21 and for hanging it from a hook or the like. Furthermore, the surface plate 1 is arranged so that the positioning jig 23 for positioning the lower plate 20, the thin plate materials 11, 12, and the upper plate 21 is located between the hanging piece 22 and the arm 17.
It is fixed on both sides of 3. Both ends of the upper plate 21 positioned by the positioning jig 23 are positioned below the hydraulic jack 18, and both ends of the upper plate 21 are moved downward by the hydraulic jack 18 via the holding jig 24. Pressed by This holding jig 24 is made of shaped steel and is used to hold the upper plate 2.
1 to prevent the pressing force of the hydraulic jack 18 from being limited to a local area and not being able to sufficiently press the thin plates 11 and 12.

Further, a strain adjustment spacer 25 is interposed between the lower plate 20 and the surface plate 13 to effectively apply reverse strain. This spacer 25 is made of thin plate materials 11 and 12.
It is arranged at the center of the total length L, and its height h is adjusted as appropriate depending on the thickness and total length L of the thin plates 11 and 12.

Therefore, in such a device, the thin plate material 1
The left and right side parts 11a and 12a of 1 and 12 are attached to the lower plate 2.
0 and the upper plate 21, and then attach it with the spacer 25.
When placed on the upper surface of the surface plate 13 with the center at the center, its both sides fitted into the positioning jig 23, and both ends pressed by the hydraulic jacks 18, the pressing force will be increased as shown in FIG. Depending on the load, lower plate 20, thin plate 1
1, 12, and the upper plate 21 are integrated into a spacer 25.
The part is curved so that it swells, and the thin plate material 11,1
2 is given a reverse strain in the height direction of the edge joint portions 11b and 12b. Here, since the left and right side portions 11a and 12a of the thin plate materials 11 and 12 are pinched by the lower plate 20 and the upper plate 21, the generation of wrinkles on the left and right side portions 11a and 12a due to bending is prevented. and thereby the edge joint portions 11b, 12
b is restrained to prevent the occurrence of wrinkles in the edge joint portions 11b and 12b, and as a result, reverse strain is applied to the edge joint without causing lateral waviness in the edge joint portion. In this state, the thin plate material 11,
If the upper ends of the 12 edge joint portions 11b and 12b are edge joint welded, reverse strain has been applied in advance, so
Strain and deformation are corrected by welding shrinkage, and a straight welded product can be obtained. After welding, the hydraulic jack 18 is removed by pulling out the pin 16 and rotating the arm 17 around the pin 15, and by releasing the fixation, the lower plate 20, the thin plate material 11,
12. The upper plate 21 can be removed from the surface plate 13.

<Effects of the Invention> As described above in detail with reference to one embodiment, according to the present invention, the left and right sides of the thin plate material to be welded are clamped from both upper and lower surfaces by the thick plate material, and the thick plate material is Since the reverse strain is applied to the thin plate material in one piece, the clamping pressure from the thick plate materials on both the left and right sides prevents the occurrence of lateral waviness at the edge joint, and provides ideal reverse strain. It becomes possible to easily correct edge joint welding distortion of plate materials.

[Brief explanation of the drawing]

FIG. 1 is a side view of an apparatus according to an embodiment of the present invention showing a state in which a reverse strain is applied to a thin plate, FIG. 2 is a side view in a state in which no reverse strain is applied, and FIG.
Figure 4 is a plan view of the same, Figure 4 is an enlarged sectional view of Figure 2, Figure 5 is a perspective view of the material to be welded, which is the object of the present invention, and Figure 6 shows the state of welding distortion in the material to be welded. FIG. 7 is a perspective view showing the occurrence of wrinkles when the material to be welded is curved. In the drawing, 11 and 12 are thin plate materials, 11a and 12a
are both left and right sides, 11b and 12b are edge joint parts,
13 is a surface plate, 17 is an arm, 18 is a hydraulic jack, 19 is a thick plate, 20 is a lower plate, 21 is an upper plate, 2
5 is a spacer.

Claims (1)

[Claims] 1. Two thin plates having an L-shaped cross section are pasted together to form a left and right side portion and an upwardly projecting edge joint portion, and then the upper edge of the edge joint portion is edge joint welded. When welding, the left and right sides of the thin plate material to be welded are clamped from above and below by a thick plate material that covers the entire surface, and integrally with this thick plate material, welding is performed on the thin plate material in the height direction of the edge joint portion. A method for preventing distortion in thin plate welding, characterized by applying a strain in the opposite direction to the strain before welding. 2. A lower plate that covers the lower surface of the left and right sides of the material to be welded, which is made by laminating two thin plates with an L-shaped cross section so as to form both the left and right sides and an upwardly projecting edge joint part, and the left and right sides. A thick plate material consisting of an upper plate that covers the upper surface and has a slit opened into which the edge joint portion is inserted, and the left and right side portions of the workpiece to be welded are clamped from above and below by the thick plate material. A hydraulic jack and a spacer that apply strain in the opposite direction to the welding strain in the height direction of the edge joint portion to the material to be welded, an arm that supports the hydraulic jack, and these thick plate materials, the hydraulic jack, the arm, and the spacer are mounted. 1. A thin plate welding distortion prevention device, comprising: a surface plate on which to place the material;