JP6431745B2 - Steel plate for welding backing - Google Patents

Description

  The present invention relates to a steel plate for welding backing, and more particularly to a steel plate for welding backing used for butt welding of a welding base material that is a steel pipe and bent according to the inner dimensions of the welding base material. is there.

As a method of joining a square steel pipe, which is often used for steel building columns, a steel pipe 102 as shown in FIG. 7 is welded to a steel plate (called a diaphragm) 103, and the beam 104 is attached to the diaphragm steel plate 103. A so-called through-diaphragm joining method for welding is often used. In the case of adopting this joining type, butt welding is generally used for welding the steel pipe as a column and the diaphragm steel plate, and a backing metal is used for welding. This backing metal is usually made by bending a flat bar into a U-shape or the like.
Examples of the welding base material as described above include polygonal steel pipes such as rectangular steel pipes, and elliptical steel pipes.

The gap between the inner surface of the curved portion of the steel pipe and the backing metal needs to be as close as possible in order to achieve good welding. In the cold-formed square steel pipe design and construction manual, the gap is specified as 1.5 mm or less, especially 0.5 mm or less is recommended for robot welding. In some cases, welding defects may occur.
As a matter of course, square steel pipes are not completely arc-shaped due to manufacturing errors, etc., which makes it difficult to manufacture the backing metal and increases the cost, and makes it difficult for the backing metal to conform to the steel pipe. There is a problem that the mounting is difficult.

  For this reason, some proposals have been made on the method of attaching the backing metal to the steel pipe. For example, in Japanese Patent Application Laid-Open No. 4-284997, a long slit plate to be used as a backing metal is molded and cut into a cylindrical scroll that matches the inner circumferential length of the steel pipe, and this is placed at the mounting position in the steel pipe. A method is shown in which a steel pipe is rolled and pressed against the inner wall of the steel pipe sequentially from the end with a roller or the like and fixed by spot welding. However, this method requires large-scale equipment such as a steel pipe transfer skid and a turning device, and is applicable only to a limited number of cases.

  On the other hand, as a method that can be applied without requiring such large-scale equipment, a notched groove is provided in advance in a flat steel to be used as a backing metal as shown in Japanese Utility Model Publication No. 63-157497. Sometimes it is bent along the inner wall of the steel pipe.

  In the method of previously providing grooves in the flat steel of Japanese Utility Model Publication No. 63-157497, four square grooves each having a certain width are provided at positions corresponding to the respective corner portions of the steel pipe. Has been. However, in the backing metal shown in the embodiment, a dent is formed on the back surface of the portion where the groove was provided, resulting in a bend in a polygonal line, thereby creating a gap between the inner wall of the steel pipe and poor welding. That is, it becomes a defect in the root portion. This Japanese Utility Model Publication No. 63-157497 describes that the groove of the backing metal is appropriately changed in shape, size, depth, and number of pitches. There is no indication of what to do.

  With respect to the above problems, in Japanese Patent Laid-Open No. 8-155679, even when there is variation in the curvature of the inner surface of the steel pipe, the gap can be kept as small as possible to the extent that there is no problem in welding, and processing is performed. Steel plates for easy backing metal have been proposed and used in practice.

  The steel plate for welding backing of steel pipes disclosed in Japanese Patent Application Laid-Open No. 8-155679 is provided in a straight state for butt welding of steel pipes, and used for bending the steel pipes according to the inner dimensions of the steel pipes. A group of 8 or more and 10 or less V-grooves is provided in a portion to be applied to the curved surface portion inside, and the depth of the V-groove is 1.5 to 4 mm less than the thickness of the backing steel plate. The angle of the V groove is 90 / n degrees or more and 110 / n degrees or less, where n is the number of V grooves in a group.

JP-A-4-284997 Japanese Utility Model Publication No. 63-157497 JP-A-8-155679

  In the above steel plate for backing, since the shape of each groove of the groove group is the same, when it is bent, it bends uniformly in each groove portion and is applied to the inner surface of the corner portion of the steel pipe. As shown in Fig. 2, the center part contacts the inner surface of the corner part, and both sides thereof are separated from the straight part of the steel pipe, and correction is difficult.

  Then, an object of this invention is to provide the steel plate for welding backing which can attach the whole bent steel plate (backing metal) to the inner surface of a steel pipe easily by reconsidering a groove shape.

The said subject is achieved by the steel plate for welding backing of this invention of the structure of following (1)-( 10 ).
(1)
In a steel plate for welding backing, which is provided in a straight state for butt welding of a welded base metal that is a polygonal steel pipe, and is bent according to the inner dimensions of the welded base material,
A group of grooves extending in the width direction of the steel sheet are formed in parallel with each other in the longitudinal direction on the portion to be applied to the inner curved surface of each curved portion of the weld base material,
The depth of the grooves of the first group, characterized in that the gradually deeper toward the both end portions from the center, a steel sheet for welded backing of the steel pipe.
( 2 )
When the bottom surface of the groove is flat, the remaining plate thickness in the shallowest groove portion of the group of grooves is 2.0 to 2.5 mm, and the remaining plate thickness in the deepest groove portion is 1.5 to 2 mm. The steel plate for welding backing of (1 ), which is 0.0 mm.
( 3 )
The steel sheet for welding backing according to any one of (1) to ( 2 ), wherein the number of grooves in the group is 4 or more.
( 4 )
The steel sheet for welding backing according to any one of (1) to ( 3 ), wherein the bent shape is an “L” shape, a “B” shape, or a “U” shape.
( 5 )
The shape of the groove is an arc shape or an elliptical arc shape in which the depth at the edge of the steel plate is shallower than the depth at the center portion, and the operator can bend without using a jig, and gas shield arc welding is performed. The steel sheet for welding backing according to any one of (1) to ( 4 ), wherein the steel sheet is configured not to come off when it is performed.
( 6 )
The minimum remaining plate thickness portion of the group of grooves is at the center in the width direction of the steel plate, and the minimum remaining plate thickness in the shallowest groove portion of the group of grooves is 1.7 to 2.2 mm. ( 5 ), the minimum remaining plate thickness portion in the groove forming portion in the deepest groove portion is centered in the width direction of the steel plate, and the minimum remaining plate thickness is 1.2 to 1.7 mm. Steel plate for application.
( 7 )
( 5 ) or ( 6 ) the steel sheet for welding backing, wherein the maximum remaining thickness is at both edges of the steel sheet.
( 8 )
The steel sheet for welding backing according to ( 5 ), wherein the groove has an arc shape and a radius of 50 to 255 mm.
( 9 )
The steel sheet for welding backing according to ( 5 ), wherein the major axis of the groove shape is an elliptical arc shape parallel to the steel sheet surface, and the flatness is 0.7 or less (not including 0).
( 10 )
A welding backing metal formed by bending the welding backing steel plate of any one of (1) to ( 9 ).

  In the steel sheet for welding backing of the present invention, the depth of the grooves at both ends of the group of grooves provided in the portion corresponding to the corner portion of the square steel pipe is made deeper than the depth of the other grooves. When the steel plate (backing metal) bent in this way is applied to the corner of a square steel pipe (see Fig. 5), the backing metal is in a state where the central part of the corner is floated. Therefore, if this part is struck with a hammer or the like, the state along the corner can be made clean.

  Moreover, in the steel sheet for welding backing of the present invention, when the shape of the bottom of the groove is an arc shape or an elliptical arc shape, the depth of the groove for winding the steel sheet is uniform as in the conventional steel sheet for welding backing. Since a groove having a deeper portion can be formed as compared with the case, the steel plate can be bent more easily. Further, the depth of the groove at the welding start portion (corresponding to one of both sides of the steel plate) where a large arc current is generated can be made shallower than the groove of the conventional steel sheet for welding backing, and thus the remaining plate thickness is increased. Since the heat capacity can be increased, it is possible to prevent welding from being lost. That is, the steel sheet for welding backing of the present invention is easier to bend than the conventional steel sheet, and further, there is no weld drop.

FIG. 1 is a perspective view showing, as an upper surface, a surface to be the outer side of a steel sheet for welding backing having a plurality of cutout grooves for a circular steel pipe according to an embodiment of the present invention. FIG. 2 is a front view in the long side direction of the steel sheet for welding backing in FIG. FIG. 3 is a front view showing a state in which the steel sheet for welding backing in FIG. 1 is bent and installed in a square steel pipe. FIG. 4 is a cross-sectional view for explaining the shape of the grooves of the backing steel plate shown in FIGS. 1 and 2. FIG. 5 is a view showing a state in which the steel sheet for welding backing shown in FIGS. 1 and 2 is bent and applied to a corner portion of a square steel pipe. FIG. 6 is a diagram schematically showing a state at the start of welding. FIG. 7 is a diagram illustrating an example of a method of using a circular steel pipe. FIG. 8 is a view showing a state in which a conventional steel sheet for welding backing is bent and applied to a corner portion of a square steel pipe.

Hereinafter, a steel plate for welding backing of a square steel pipe according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the steel sheet for welding backing of the present invention, any polygonal steel pipe such as a square steel pipe can be used as a welding base material. In the following description, a steel pipe that is a welding base material will be described as a square steel pipe.
1 is a perspective view showing a steel pipe for welding backing of a steel pipe according to an embodiment of the present invention, FIG. 2 is a front view of the steel sheet for backing of FIG. 1, and FIG. 3 is a steel sheet for backing of FIG. It is the front view which represented with the state bent along the curved part of the steel pipe.

  As shown in the perspective view of FIG. 1, the backing steel plate 1 is provided with a group of grooves 10 at locations corresponding to corner portions of a square steel pipe. It is preferable that the distance between the center portions of each group of grooves of the backing steel plate and the distance between the center portions of the curved surface portions of the inner surfaces of the adjacent corner portions of the square steel pipe are substantially matched. The backing metal formed by bending the steel plate 1 for welding backing is used by being installed on the welding base material 102 as shown in FIG. In the illustrated example, there are groove groups at two locations, but it is also possible to weld the entire inner periphery of the square column with a single backing metal using a groove group provided at four locations.

  The side surface shape of the groove 10 is preferably a square shape whose both side surfaces are parallel to each other as well shown in FIG. The width of each groove 10 is 4 mm or less, preferably 2 mm or less, and particularly preferably 1.75 mm or less. This width is preferably as narrow as possible in view of the above-mentioned welding omission, but the number of grooves increases, and processing takes time and cost. Currently, the lower limit is about 1.0 mm because of the relationship of the saw blade.

  In the present invention, the number of grooves is 4 or more, preferably 12 or less, particularly 8 to 10 in each group. That is, it is preferable to provide 4 or more and 12 or less grooves in the range of the length of the portion that should contact the curved surface inside the square column when the backing steel plate is bent.

  Moreover, when arrange | positioning a groove | channel at equal intervals in each group, it is preferable that a pitch shall be 2.55 mm or more. If this pitch is less than the above value, the remaining amount of iron in the groove forming portion becomes insufficient, and the above-mentioned disconnection is likely to occur during welding. This upper limit is that if the pitch becomes too large, the bent portion of the backing steel plate is not substantially arcuate, but polygonal, and the sides of the polygon and the corners of the square steel pipe Since the gap with the arc becomes large, it is desirable to set the pitch so that the gap is 0.4 mm or less.

  When the groove 10 is square as described above, it is preferable that both side walls of the groove do not interfere with each other (contact) when the backing steel plate is bent along the corner of the square steel pipe. If it is a degree)

  Further, one to four grooves may be added to deal with errors in the length and curvature of each side of the square steel pipe, that is, as an adjustment allowance. The backing steel plate according to the present invention can be bent easily as will be described later, so when it is bent and then fitted to the corner of the corner column, if it does not fit, it can be bent back and bent again. Therefore, this adjustment allowance is particularly useful.

  Further, one to four grooves may be added to deal with errors in the length and curvature of each side of the square steel pipe, that is, as an adjustment allowance. The backing steel sheet according to the present invention can be bent easily as will be described later, so when it is bent and then fitted to the corner of the corner column, if it does not fit, it can be bent back and bent again. Therefore, this adjustment allowance is particularly useful.

  In the embodiment of the present invention, the depth of the grooves 10 in each group is such that at least the depth of the grooves at both ends is deeper than the depth of the center groove, that is, the remaining plate thickness of the portion provided with at least the grooves at both ends. Is made smaller and the steel sheet is preferably easily bent at both ends. Preferably, as shown in FIG. 2, it is desirable that the depth of the groove in each group is gradually increased from the central portion toward the both end portions.

In the embodiment of the present invention, the depth of the grooves 10 in each group is such that at least the depth of the grooves at both ends is deeper than the depth of the center groove, that is, the remaining plate thickness of the portion provided with at least the grooves at both ends. Is made smaller and the steel sheet is preferably easily bent at both ends. Preferably, as shown in FIG. 2, it is desirable that the depth of the groove in each group is gradually increased from the central portion toward the both end portions.
When the bottom surface of the groove is flat, the remaining plate thickness at the deepest groove depth is 1.5 to 2.0 mm, and the remaining plate thickness at the shallowest groove depth is 2.0 to 2 mm. .5 mm.

  FIG. 3 is a plan view showing a usage state of the backing steel plate 20. When attaching the backing metal to the steel pipe 102, the operator bends the backing steel plate 1 manually as shown in the figure to attach it to the welded base metal. As described above, at the initial stage where the backing metal is attached to the steel pipe, the bending state of the steel plate is preferably in the state shown in FIG.

  It is preferable that the cross-sectional shape seen from the longitudinal direction of the steel plate of the groove 10 formed with the welding backing steel plate 1 is the shape shown in FIG.

  The shape (bottom shape) of the groove 10 is an arc shape or an elliptical arc shape in which the depth at the edge b of the steel plate is shallower than the depth at the central portion a. It is preferable that the minimum remaining plate thickness portion in the groove forming portion is at the center in the width direction of the steel plate. The minimum remaining plate thickness portion of the group of grooves is at the center in the width direction of the steel plate, and the minimum remaining plate thickness in the shallowest groove portion of the group of grooves is 1.7 to 2.2 mm. Among these, it is preferable that the minimum remaining plate thickness portion in the groove forming portion in the deepest groove portion is at the center in the width direction of the steel plate, and the minimum remaining plate thickness is 1.2 to 1.7 mm. If the minimum remaining plate thickness a is less than the above range, weld drop is likely to occur at that point, while if it exceeds the above range, the effect of ease of bending compared to the conventional one is reduced.

  The maximum remaining plate thickness in the groove forming portion is preferably 1.8 mm or more and 4.1 mm or less. If the maximum remaining plate thickness exceeds the above range, the effect of bendability as compared with the conventional one is reduced.

  When the groove has an arc shape, the radius is preferably 50 mm to 255 mm. When the groove has an elliptical arc shape whose major axis is parallel to the steel plate surface, the flatness is preferably 0.7 or less (not including 0 (arc)).

  The welding steel plate for welding has a “L” shape, a “B” shape, a “U” shape, a circular shape, an oval shape, etc. Is mentioned.

  FIG. 6 shows a welded state of a steel pipe and a diaphragm using a backing metal formed by bending the welding backing steel plate 1 shown in FIG. 1. In the initial stage of welding in which a large arc current is generated, the welding machine Since the arc is applied to the portion of the backing metal having a high heat capacity and a large remaining plate thickness, it is possible to prevent welding from being lost.

1: Steel plate for welding backing 10: Notch groove 102: Welding base material (square steel pipe)
103: Welding base material (diaphragm)
104: Beam

Claims (10)

In the steel plate for welding backing used for butt welding of the welded base metal which is a polygonal steel pipe, bent according to the inner dimensions of the welded base material,
A group of grooves extending in the width direction of the steel sheet are formed in parallel with each other in the longitudinal direction on the portion to be applied to the inner curved surface of each curved portion of the weld base material,
A steel pipe for welding backing of a steel pipe, wherein the depth of the group of grooves gradually increases from the center toward both ends . When the bottom surface of the groove is flat, the remaining plate thickness in the shallowest groove portion of the group of grooves is 2.0 to 2.5 mm, and the remaining plate thickness in the deepest groove portion is 1.5 to 2 mm. The steel sheet for welding backing according to claim 1, which is 0.0 mm. The steel sheet for welding backing according to any one of claims 1 to 2 , wherein the number of grooves in the group is 4 or more. The steel sheet for welding backing according to any one of claims 1 to 3 , wherein a shape when bent is an "L" shape, a "B" shape, or a "U" shape. The shape of the groove is an arc shape or an elliptical arc shape in which the depth at the edge of the steel plate is shallower than the depth at the center portion, and the operator can bend without using a jig, and gas shield arc welding is performed. The steel sheet for welding backing according to any one of claims 1 to 4 , wherein the steel sheet is configured so as not to come off when it is performed. The minimum remaining plate thickness portion of the group of grooves is at the center in the width direction of the steel plate, and the minimum remaining plate thickness in the shallowest groove portion of the group of grooves is 1.7 to 2.2 mm. The weld backing according to claim 5 , wherein the minimum remaining plate thickness portion in the groove forming portion in the deepest groove portion is centered in the width direction of the steel plate, and the minimum remaining plate thickness is 1.2 to 1.7 mm. Steel plate. The steel plate for welding backing according to claim 5 or 6 , wherein the maximum remaining thickness portion is at both edges of the steel plate. The steel sheet for welding backing according to claim 5 , wherein the groove has an arc shape and a radius of 50 to 255 mm. The steel sheet for welding backing according to claim 5 , wherein the major axis of the groove shape is an elliptical arc shape parallel to the surface of the steel sheet, and the flatness is 0.7 or less (not including 0). A welding backing metal formed by bending the steel sheet for welding backing according to any one of claims 1 to 9 .