JP2012110950A - Welded structure and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welded structure where occurrence of cracks in a boxing welding section can be suppressed while restraining the increase of production steps, and a method for producing the same.SOLUTION: The welded structure 100 includes a boxing welding section 30 having a first short bead part 320a and a first extending bead part 330a. The first extending bead part 330a is connected to the first short bead part 320a, and extends in a direction opposite to a planar member 20 in a longitudinal direction. The width 320W of the first short bead part 320a is smaller as it is separated from the planar member 20 in a transverse direction. The whole width 330Wmax of the first extending bead part 330a is smaller than the whole width 320Wmax of the first short bead part 320a in the transverse direction.

Description

  The present invention relates to a welded structure having a rotating weld and a method for manufacturing the same.

Conventionally, a base member having a base surface, a plate-like member standing on the base surface and having an abutting portion that comes into contact with the base surface, and turn welding surrounding the contact portion of the plate-like member on the base surface And a welded structure including a portion is widely used.
In such a welded structure, when a load is applied to the foundation member, stress concentrates on the boundary between the surface of the turning welded portion and the foundation surface of the foundation member (hereinafter referred to as “toe”). A crack starting from the toe may turn and occur in the weld.

  Therefore, in order to suppress the occurrence of cracks in the rotating welded portion, a method of forming a groove in the rotating welded portion by ultrasonic impact treatment has been proposed (see Patent Document 1). According to this technique, it is said that stress concentration on the toe can be alleviated by improving the shape of the toe by forming a groove.

JP 2004-167516 A

However, in the manufacturing method described in Patent Document 1, a process of processing the rotating weld itself is required after the process of forming the rotating weld, which increases the manufacturing process.
This invention is made | formed in view of the above-mentioned situation, and it aims at providing the welding structure which can suppress generation | occurrence | production of the crack in a turning welding part, suppressing the increase in a manufacturing process, and its manufacturing method. .

  The welded structure according to the first aspect of the present invention includes a base member, a plate-like member, and a turn welded portion. The foundation member has a foundation surface. The plate-like member is erected on the foundation surface. The plate-like member includes a first main surface perpendicular to the base surface, a second main surface provided opposite to the first main surface, and a first side surface communicating with the first main surface and the second main surface. And a second side surface provided opposite to the first side surface, and a contact portion that contacts the base surface. The turning welded portion surrounds the contact portion of the plate-like member on the base surface. The turning welded portion has a first long bead portion, a second long bead portion, a first short bead portion, and a first extending bead portion. The first longitudinal bead portion is disposed along the longitudinal direction perpendicular to the first side surface on the first main surface. The second longitudinal bead portion is disposed along the longitudinal direction on the second main surface. The first short bead portion is disposed on the first side surface and connected to the first long bead portion and the second long bead portion. The first extending bead portion is connected to the first short bead portion and extends in the opposite direction to the plate-like member in the longitudinal direction. In the short direction that intersects the longitudinal direction, the width of the first short bead portion decreases as the distance from the plate member increases. In the short direction, the full width of the first extended bead portion is smaller than the full width of the first short bead portion.

  According to the welded structure according to the first aspect of the present invention, since the first extended bead portion extends in the longitudinal direction from the first short bead portion, the distal end portion of the first extended bead portion is It can be separated from the plate member. Thereby, the total length of the boundary (hereinafter, referred to as “short stop”) between the surface and the base surface of each of the first short bead portion and the first extended bead portion can be increased. Therefore, since stress concentration at the short toe is suppressed, the generation of cracks starting from the short toe at the turn welded portion can be suppressed. Moreover, since the width | variety of a 1st short bead part is so small that it leaves | separates from a plate-shaped member, the connection from a 1st short bead part to a 1st extended bead part can be made smooth in planar view. . Therefore, it can suppress that stress concentrates on the connection point of a 1st short bead part and a 1st extension bead part among short stop ends. As a result, it is possible to further suppress the generation of cracks in the turn welded portion. Furthermore, compared with the case where the width | variety of a 1st short bead part is set uniformly, the welding amount (namely, usage-amount of the metal material added during welding) can be decreased. Further, the full width of the first extending bead portion is smaller than the full width of the first short bead portion. Therefore, compared with the case where the 1st extended bead part is formed wider than the 1st short bead part, the amount of welding can be decreased more. Furthermore, since the turning welded part can be formed only by the welding process, there is no need to add a process for processing the turning welded part itself. Therefore, an increase in manufacturing process can be suppressed.

The welded structure according to the second aspect of the present invention is related to the first aspect, and in the short direction, the full width of the first short bead portion is larger than the thickness of the plate-like member.
According to the welded structure according to the second aspect of the present invention, the overall length of the short toe end is made longer than when the entire width of the first short bead portion is equal to or less than the thickness of the plate-like member. be able to. As a result, it is possible to further suppress the generation of cracks in the turn welded portion.

The welded structure according to the third aspect of the present invention relates to the first or second aspect, and in the short-side direction, the full width of the first extending bead portion is smaller than the thickness of the plate-like member.
According to the welded structure according to the third aspect of the present invention, the amount of welding can be reduced as compared with the case where the entire width of the first extending bead portion is equal to or greater than the thickness of the plate-like member.

The welded structure according to the fourth aspect of the present invention relates to any one of the first to third aspects, and in the short-side direction, the width of the first extending bead portion is separated from the first short-bead portion. Small enough.
According to the welded structure according to the fourth aspect of the present invention, the amount of welding can be reduced as compared with the case where the width of the first extending bead portion is set uniformly.

The welded structure according to the fifth aspect of the present invention relates to any one of the first to fourth aspects, and in the longitudinal direction, the length of the first extended bead portion is the length of the first short bead portion. Bigger than that.
According to the welded structure according to the fifth aspect of the present invention, the amount of welding is less than that in the case where the length of the first extended bead portion is equal to or greater than the length of the first short bead portion. can do.

The welded structure according to the sixth aspect of the present invention relates to any one of the first to fourth aspects, and in the longitudinal direction, the length of the first extended bead portion is the length of the first short bead portion. Smaller than that.
According to the welded structure according to the sixth aspect of the present invention, since the connection from the first short bead portion to the first extended bead portion can be made smoother, the first short bead out of the short toe ends. It can suppress more that stress concentrates on the connection point of a part and a 1st extension bead part.

A welded structure according to a seventh aspect of the present invention relates to any one of the first to sixth aspects, and includes a surface and a base surface of the first extended bead portion in a longitudinal section perpendicular to the base surface and one side surface. The extended bead toe angle formed by is larger than the long bead toe angle formed by the surface of the first long bead portion and the base surface in a short cross section perpendicular to the base surface and the first main surface.
According to the welded structure according to the seventh aspect of the present invention, compared to the case where the extended bead toe angle is equal to or less than the longitudinal bead toe angle, the surface and the base surface of the first extended bead portion Can be connected smoothly. Therefore, it can suppress that stress concentrates on the boundary of the surface of a 1st extension bead part, and a base surface among short toes. As a result, it is possible to further suppress the generation of cracks in the turn welded portion.

The welded structure according to the eighth aspect of the present invention relates to the seventh aspect, and the short bead connection angle formed between the surface of the first extended bead part and the surface of the first short bead part in the longitudinal section is It is larger than the longitudinal bead toe angle.
According to the welded structure according to the eighth aspect of the present invention, the surface of the first short bead portion and the first extension are compared to the case where the short bead connection angle is equal to or less than the longitudinal bead toe angle. The surface of the bead portion can be smoothly connected. Therefore, it can suppress that stress concentrates on the boundary of the surface of the 1st short bead part, and the surface of the 1st extension bead part. As a result, it is possible to suppress the occurrence of a crack starting from the boundary between the first short bead portion and the first extended bead portion in the turn welded portion.

The welded structure according to the ninth aspect of the present invention relates to the eighth aspect, and the extended bead toe angle is larger than the short bead connection angle.
According to the welded structure according to the ninth aspect of the present invention, compared to the case where the extended bead toe angle is equal to or less than the short bead coupling angle, the surface and the base surface of the first extended bead portion Can be connected more smoothly. Therefore, it can suppress more that stress concentrates on the boundary of the surface of a 1st extension bead part, and a base surface among short toe ends.

A welded structure according to a tenth aspect of the present invention relates to any one of the first to ninth aspects, wherein the turning welded portion is disposed on the second side surface, and the first longitudinal bead portion and the second longitudinal bead are arranged. A second short bead portion coupled to the first portion, and a second extended bead portion coupled to the second short bead portion and extending in a direction opposite to the plate-like member in the longitudinal direction.
According to the welded structure according to the tenth aspect of the present invention, the second extending bead portion can obtain the same effect as that of the first extending bead portion described above. It is possible to suppress the occurrence of cracks in the welded part.

The manufacturing method of the welded structure according to the eleventh aspect of the present invention includes a standing step, a first short bead portion forming step, a first extended bead portion forming step, and a first longitudinal bead portion forming step. And a second longitudinal bead portion forming step. In the erecting step, on the foundation surface of the foundation member, the first principal surface perpendicular to the foundation surface, the second principal surface provided opposite to the first principal surface, the first principal surface and the second principal surface A plate-like member having a first side surface communicating with the second side surface and a second side surface provided opposite to the first side surface. In the first short bead portion forming step, after the boundary between the first side surface and the base surface is welded, the welding width in the short direction intersecting the longitudinal direction perpendicular to the first side surface is gradually reduced in the longitudinal direction. Weld along. In the first extending bead portion forming step, welding is performed straight from the first short bead portion along the longitudinal direction. In the first longitudinal bead portion forming step, the boundary between the first main surface and the base surface is welded. In the second longitudinal bead portion forming step, the boundary between the second main surface and the base surface is welded.
According to the method for manufacturing a welded structure according to the eleventh aspect of the present invention, the rotary weld is formed only by the welding process. Therefore, it is not necessary to add a process for processing the turned weld itself, so that an increase in the manufacturing process can be suppressed.

The manufacturing method of the welded structure according to the twelfth aspect of the present invention relates to the eleventh aspect, and includes a second short bead portion forming step of welding a boundary between the second side surface and the base surface, and a second short side. After the bead portion forming step, a second extended bead portion forming step of welding straight from the second short bead portion in the longitudinal direction is provided.
According to the method for manufacturing a welded structure according to the twelfth aspect of the present invention, since the second short bead portion can be formed only by the welding process, an increase in the manufacturing process can be avoided. Moreover, it can suppress that a crack generate | occur | produces in a turn welding part in the longitudinal direction both sides of a plate-shaped member.

  The manufacturing method of the welded structure according to the thirteenth aspect of the present invention relates to the eleventh or twelfth aspect, wherein the first longitudinal bead portion forming step and the second longitudinal bead portion forming step are the first extended bead portion. Performed after the forming step.

  ADVANTAGE OF THE INVENTION According to this invention, the welding structure which can suppress generation | occurrence | production of the crack in a turning weld part, suppressing the increase in a manufacturing process, and its manufacturing method can be provided.

It is a perspective view of the welding structure concerning an embodiment. It is a perspective view of the welding structure concerning an embodiment. It is a top view of the welding structure concerning an embodiment. FIG. 4 is a partially enlarged view of FIG. 3. It is sectional drawing in the XX line of FIG. It is sectional drawing in the YY line | wire of FIG. It is the elements on larger scale of FIG. It is a figure for demonstrating the manufacturing method of the welded structure which concerns on embodiment. It is a top view of the welding structure concerning an embodiment. It is an enlarged plan view of the 1st short bead part concerning an embodiment. It is an enlarged plan view of the 1st short bead part concerning an embodiment. It is an enlarged plan view of the 1st short bead part concerning an embodiment. It is a perspective view of the welding structure concerning an example. It is a perspective view of the welding structure concerning a comparative example. It is a graph which shows the result of a uniaxial tension fatigue test.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Configuration of welded structure)
The configuration of the welded structure 100 according to the embodiment will be described with reference to the drawings. FIG. 1 is a perspective view of a welded structure 100 according to the present embodiment as viewed from one side in the longitudinal direction. FIG. 2 is a perspective view of the welded structure 100 according to the present embodiment as viewed from the other side in the longitudinal direction. FIG. 3 is a plan view of the welded structure 100 according to the present embodiment.
The welded structure 100 includes a base member 10, a plate-like member 20, and a rotating welded part 30. The welded structure 100 is disposed, for example, inside a construction machine, and a tensile load or a compressive load is repeatedly applied along a longitudinal direction described later.
The foundation member 10 is a foundation of the welded structure 100. The foundation member 10 has a foundation surface 10S. In this embodiment, although the base member 10 is formed in plate shape, it is not restricted to this. The base member 10 is made of a metal material.

The plate-like member 20 is erected on the base surface 10S. The plate-like member 20 has a contact portion 20E (not shown in FIGS. 1 and 2; see FIGS. 5 and 6) that is in contact with the base surface 10S.
Further, the plate-shaped member 20 has a first major surface 20M _1, a second main surface 20M _2, the first side surface 20 N _1, the second side 20 N _2, a. The first main surface 20M ₁ is provided perpendicular to the base surface 10S. The second main surface 20M ₂ is perpendicular to the base surface 10S and is provided opposite to the first main surface 20M ₁ . The first side surface 20N ₁ is perpendicular to the base surface 10S and communicates with the first main surface 20M ₁ and the second main surface 20M ₂ . The second side surface 20N ₂ is perpendicular to the base surface 10S and is provided opposite to the first side surface 20N ₁ . The areas of the first main surface 20M ₁ and the second main surface 20M ₂ are larger than the areas of the first side surface 20N ₁ and the second side surface 20N _2, respectively. The plate member 20 is made of a metal material. The metal material constituting the plate-like member 20 may be the same as or different from the metal material constituting the base member 10.

Here, in this embodiment, a direction perpendicular to the first side surface 20N ₁ and the second side surface 20N ₂ (that is, a direction parallel to the first main surface 20M ₁ and the second main surface 20M ₂ and the base surface 10S). Is referred to as the “longitudinal direction”. Further, the direction perpendicular to the first main surface 20M ₁ and the second main surface 20M ₂ (that is, the direction parallel to the first side surface 20N ₁ and the second side surface 20N ₂ and the base surface 10S) is defined as the “short direction”. Called.

  The rotating weld 30 is disposed on the base surface 10S. The rotating welded portion 30 surrounds the outer periphery of the contact portion 20E (see FIGS. 5 and 6) of the plate-like member 20. The turning welded portion 30 is formed by welding the base member 10 and the plate-like member 20. Therefore, the turning welded portion 30 includes a metal material constituting the base member 10, a metal material constituting the plate-like member 20, and a metal material added during welding (so-called “filler material”. Including a “wire”) and a weld metal that has been melted and solidified. For example, automatic welding (robot arc welding or the like) using a welding robot is used for welding the base member 10 and the plate-like member 20, but is not limited thereto.

In the present embodiment, the turn welded portion 30 includes a first long bead portion 310a, a second long bead portion 310b, a first short bead portion 320a, a second short bead portion 320b, and a first extended bead. Part 330a and second extending bead part 330b. However, each bead part is mutually connected, and the rotation welding part 30 is formed continuously as a whole.
The first longitudinal bead portion 310a, in the first main surface 20M _1, are arranged along the longitudinal direction. Both longitudinal ends of the first long bead portion 310a are connected to the first short bead portion 320a and the second short bead portion 320b. The second longitudinal bead portion 310b, in the second main surface 20M _2, are arranged along the longitudinal direction. Both longitudinal ends of the second long bead portion 310b are connected to the first short bead portion 320a and the second short bead portion 320b. The first longitudinal bead portion 310a and the second longitudinal bead portion 310b are arranged symmetrically with respect to the plate-like member 20, and have the same configuration.

The first short bead portion 320a is arranged along the short side direction on the first side surface 20N ₁ . Both ends in the short direction of the first short bead portion 320a are connected to the first long bead portion 310a and the second long bead portion 310b. The second lateral bead portion 320b, in the second aspect 20N on _2, are arranged along the widthwise direction. Both ends of the second short bead portion 320b in the short direction are connected to the first long bead portion 310a and the second long bead portion 310b. The first short bead portion 320a and the second short bead portion 320b are arranged symmetrically with respect to the plate-like member 20 and have the same configuration.

  The first extended bead portion 330a is connected to the tip of the first short bead portion 320a (see “short bead tip portion 322” in FIG. 4). The first extending bead portion 330a is disposed along the longitudinal direction. The first extending bead portion 330 a extends from the first short bead portion 320 a in the direction opposite to the plate-like member 20. The second extended bead portion 330b is connected to the tip of the second short bead portion 320b. The second extending bead portion 330b is disposed along the longitudinal direction. The second extending bead portion 330 b extends from the second short bead portion 320 b in the direction opposite to the plate-like member 20. The 1st extension bead part 330a and the 2nd extension bead part 330b are arranged symmetrically on the basis of plate-like member 20, and have the same composition.

(Configuration of rotating weld)
Next, a detailed configuration of the rotary weld 30 according to the present embodiment will be described with reference to the drawings. FIG. 4 is a partially enlarged view of FIG. FIG. 5 is a cross-sectional view taken along line XX of FIG. 6 is a cross-sectional view taken along line YY of FIG.
In the following, the configuration of the first long bead portion 310a, the first short bead portion 320a, and the first extended bead portion 330a will be mainly described, and the second long bead portion 310b and the second short bead portion 320b will be described. The description of the configuration of the second extending bead portion 330b is omitted.

<1. Width of first short bead portion 320a and first extended bead portion 330a>
First, the width of the first short bead portion 320a and the first extended bead portion 330a in the short direction will be described with reference to FIG.
The first short bead portion 320a is formed in a tapered shape from the plate-like member 20 toward the first extending bead portion 330a. Specifically, the width 320 </ b> W in the short direction of the first short bead portion 320 a becomes smaller as the distance from the plate-like member 20 increases. That is, the width 320W becomes smaller as it approaches the first extending bead portion 330a. Therefore, the width 320W is largest at the short bead base end 321 of the first short bead portion 320a and is smallest at the short bead distal end 322. The overall width 320Wmax (maximum value of the width 320W) in the short direction of the first short bead portion 320a is larger than the width 20W in the short direction of the plate-like member 20.

  The first extending bead portion 330a is formed in a tapered shape along the longitudinal direction from the short bead tip portion 322 of the first short bead portion 320a. Specifically, the width 330 </ b> W in the short direction of the first extending bead portion 330 a becomes smaller as the distance from the first short bead portion 320 a and the plate-like member 20 increases. Therefore, the width 330 </ b> W is the largest at the extended bead base end 331 and the smallest at the extended bead distal end 332 of the first extended bead portion 330 a. However, in the present embodiment, since most of the first extending bead portion 330a is linearly formed along the longitudinal direction, the width 330W is substantially constant in most of the first extending bead portion 330a. It is. The total width 330Wmax (the maximum value of the width 330W) in the short direction of the first extended bead portion 330a is smaller than the full width 320Wmax in the short direction of the first short bead portion 320a. Further, the overall width 330Wmax in the short direction of the first extending bead portion 330a is smaller than the width 20W in the short direction of the plate-like member 20.

  The width 20W in the short direction of the plate member 20 corresponds to the “thickness” of the plate member 20, and is substantially constant in the longitudinal direction.

<2. Length of first short bead portion 320a and first extended bead portion 330a>
Next, the length in the longitudinal direction of the first short bead portion 320a and the first extended bead portion 330a will be described with reference to FIG.
The length 320L in the longitudinal direction of the first short bead portion 320a is smaller than the length 330L in the longitudinal direction of the first extending bead portion 330a.
The length 320L of the first short bead portion 320a is a distance in the longitudinal direction between the short bead base end portion 321 and the short bead distal end portion 322. The length 330L of the first extended bead portion 330a is a distance in the longitudinal direction between the extended bead base end portion 331 and the extended bead distal end portion 332. In the present embodiment, the short bead distal end 322 and the extended bead base end 331 partially overlap in the longitudinal direction.

<3. Cross-sectional configuration of each bead section>
Next, the cross-sectional configuration of each bead portion of the rotating welded portion 30 will be described with reference to FIGS. 5 and 6. FIG. 5 shows a cross section (hereinafter referred to as “longitudinal cross section”) of the welded structure 100 perpendicular to each of the base surface 10S and the first side surface 20N ₁ . FIG. 6 shows a cross section (hereinafter referred to as a “short cross section”) of the welded structure 100 perpendicular to each of the base surface 10S and the first main surface 20M ₁ .

First, as shown in FIG. 5, the first extending bead portion 330 a is melted into the base member 10. Specifically, the bottom portion of the first extending bead portion 330 a is melted into the base surface 10 </ b> S of the base member 10. A crater 330CR is formed at the extended bead tip 332 of the first extended bead portion 330a.
Here, the first extended bead portion 330a has an extended bead surface 330S exposed to the outside. The extended bead surface 330S of the first extended bead portion 330a and the base surface 10S of the base member 10 form an extended bead stop angle 330θ. The “stop” is a boundary between the surface of the rotary weld 30 and the base surface 10S of the base member 10.

Next, the 1st short bead part 320a is melt | dissolving in the base member 10 and the plate-shaped member 20, as shown in FIG. Specifically, the bottom portion of the first short bead portion 320 a is melted into the base surface 10 </ b> S of the base member 10, and the short bead base end portion 321 of the first short bead portion 320 a is It melts into the contact portion 20E.
Here, the first short bead portion 320a has a short bead surface 320S exposed to the outside. The first short bead portion 320a is integrally connected to the first extended bead portion 330a, the short bead surface 320S of the first short bead portion 320a, and the extension of the first extended bead portion 330a. The bead surface 330S forms a short bead connection angle 320θ.

Next, as shown in FIG. 6, the first longitudinal bead portion 310 a is melted into the base member 10 and the plate-like member 20. Specifically, the bottom portion of the first longitudinal bead portion 310a is melted into the base surface 10S of the base member 10, and the side portion of the first longitudinal bead portion 310a is melted into the contact portion 20E of the plate-like member 20. Yes.
Here, the first longitudinal bead portion 310a has a longitudinal bead surface 310S exposed to the outside. The longitudinal bead surface 310S of the first longitudinal bead portion 310a and the foundation surface 10S of the foundation member 10 form a longitudinal bead toe angle 310θ.

  In the present embodiment, the extended bead toe angle 330θ in the long cross section is larger than the long bead toe angle 310θ in the short cross section (330θ> 310θ). Further, the short bead coupling angle 320θ in the longitudinal section is larger than the longitudinal bead toe angle 310θ in the short section (320θ> 310θ). Further, the extended bead toe angle 330θ in the longitudinal section is larger than the short bead coupling angle 320θ in the longitudinal section (330θ> 320θ).

Therefore, in the present embodiment, 330θ>320θ> 310θ is satisfied.
Note that the extended bead toe angle 330θ is defined as “an angle formed by the extended bead surface 330S and the base surface 10S” as described above, but may be more specifically defined as follows. . That is, as shown in FIG. 7 (corresponding to the partially enlarged view of FIG. 5), the extended bead toe angle 330θ is “the toe point p that is a boundary point between the extended bead surface 330S and the base surface 10S, and the stop point p. It can be defined as “the angle formed by the straight line pq connecting the surface point q on the extended bead surface 330S that is separated from the end point p in the longitudinal direction by the distance r” with the base surface 10S. The interval r can be set to about 0.5 mm, for example, but is not limited thereto.
Although not shown, each of the short bead coupling angle 320θ and the long bead toe angle 310θ can be specifically defined in the same manner as the extended bead toe angle 330θ.

(Method for manufacturing a welded structure)
Next, a method for manufacturing the welded structure 100 according to the present embodiment will be described with reference to the drawings. FIG. 8 is a diagram for explaining a method of manufacturing the welded structure 100 according to the present embodiment. In FIG. 8, the weld line S (the first weld line Sa, the second weld line Sb, the third weld line Sc, the fourth weld line Sd, the fifth weld line Se, and the sixth weld at the time of forming the rotary weld 30. The line Sf is included) and the welding direction (the direction of the arrow) is shown. In this embodiment, the welding order is Sa → Sb → Sc → Sd → Se → Sf, and automatic welding is performed by the welding robot in the alphabetical order attached to the welding line.

First, the plate-like member 20 is erected on the base surface 10 </ b> S of the base member 10. Thus, each of the first main surface 20M ₁ , the second main surface 20M ₂ , the first side surface 20N ₁ , and the second side surface 20N ₂ is in contact with the base surface 10S and forms a boundary with the base surface 10S. . Although not shown, the contact portion 20E of the base member 10 is in contact with the base surface 10S.
Next, welding is performed along the first welding line Sa by a forward method according to the illustrated welding direction. Specifically, first, the welding torch (not shown) of the welding robot is moved from the starting point a1 to the turning point a2, and the boundary between the first side surface 20N ₁ and the base surface 10S is welded. Subsequently, the welding torch is moved zigzag along the longitudinal direction from the turning point a2 to the middle point a7 via the turning point a3, the turning point a4, the turning point a5, and the turning point a6, and the first side face 20N _1. Weld while gradually leaving. At this time, the welding width in the lateral direction is gradually reduced by gradually reducing the weaving width of the welding torch. Thus, the tapered first short bead portion 320a is formed.

  Next, welding is performed along the second welding line Sb by the forward method according to the illustrated welding direction. Specifically, the welding torch is moved straight from the start point b1 to the end point b2 at the same position as the middle point a7. As a result, a first extending bead portion 330a extending in the longitudinal direction from the first short bead portion 320a is formed. In addition, the crater 330CR is formed in the extended bead front-end | tip part 332 of the 1st extended bead part 330a by pulling up after hold | maintaining a welding torch in the end point b2.

Next, welding is performed along the third welding line Sc according to the welding direction according to the welding direction. Specifically, first, the welding torch is moved from the starting point c1 to the turning point c2, and the boundary between the second side surface 20N ₂ and the base surface 10S is welded. Then, folding points c2 turning point from c3, folding points c4, folding points c5, and to the midpoint c7 via the folding point c6, by moving the welding torch in a zigzag, gradually away from the second side 20 N ₂ Weld. At this time, the welding width in the lateral direction is gradually reduced by gradually reducing the weaving width of the welding torch. Thus, the tapered second short bead portion 320b is formed.

  Next, welding is performed along the fourth welding line Sd by the forward method in accordance with the illustrated welding direction. Specifically, the welding torch is moved straight from the start point d1 to the end point d2 at the same position as the middle point c7. As a result, a second extending bead portion 330b extending in the longitudinal direction from the second short bead portion 320b is formed. In addition, it is preferable to hold the welding torch for a predetermined time also at the end point d2.

Next, welding is performed along the fifth weld line Se by a forward method according to the welding direction. Specifically, the welding torch is moved from the start point e1 to the end point e2 (that is, from the second side surface 20N ₂ side toward the first side surface 20N ₁ side), and the first main surface 20M ₁ and the base surface 10S are moved. Weld the boundary. Thereby, the first longitudinal bead portion 310a arranged along the longitudinal direction is formed.
Next, welding is performed along the sixth weld line Sf by the forward method according to the welding direction. Specifically, the welding torch is moved from the start point f1 to the end point f2 (that is, from the second side surface 20N ₂ side to the first side surface 20N ₁ side), and the second main surface 20M ₂ and the base surface 10S are moved. Weld the boundary. Thereby, the second longitudinal bead portion 310b disposed along the longitudinal direction is formed.

(Function and effect)
(1) The welded structure 100 according to the present embodiment includes a rotating welded portion 30 having a first short bead portion 320a and a first extended bead portion 330a. The 1st extension bead part 330a is connected with the 1st short bead part 320a, and extends in the direction opposite to plate-like member 20 in the longitudinal direction. In the short direction, the width 320W of the first short bead portion 320a is smaller as the distance from the plate member 20 increases. In the short direction, the overall width 330Wmax of the first extended bead portion 330a is smaller than the overall width 320Wmax of the first short bead portion 320a.

  As described above, in the welded structure 100 according to the present embodiment, the first extending bead portion 330a extends in the longitudinal direction from the first short bead portion 320a, and therefore the tip of the first extending bead portion 330a. The part 332 can be separated from the plate-like member 20. Therefore, since stress concentration at the short toe is suppressed, it is possible to suppress the occurrence of cracks with the short toe at the turning welded portion 30 as a base point.

  In addition, since the width 320W of the first short bead portion 320a becomes smaller as the distance from the plate member 20 increases, the connection from the first short bead portion 320a to the first extended bead portion 330a is smooth in plan view. Can be. Therefore, it can suppress that stress concentrates on the connection point of the 1st short bead part 320a and the 1st extension bead part 330a among short stop ends. As a result, the generation of cracks in the turn welded portion 30 can be further suppressed. Furthermore, compared with the case where the width 320W of the 1st short bead part 320a is set uniformly, the amount of welding (namely, the usage-amount of the metal material added during welding) can be decreased.

Further, the overall width 330Wmax of the first extending bead portion 330a is smaller than the overall width 320Wmax of the first short bead portion 320a. Therefore, compared with the case where the 1st extended bead part 330a is formed wider than the 1st short bead part 320a, the amount of welding can be decreased more.
Furthermore, since the turn welding part 30 can be formed only by a welding process, it is not necessary to add the process of processing the turning welding part 30 itself. Therefore, an increase in manufacturing process can be suppressed.

  (2) In the welded structure 100 according to the present embodiment, the overall width 320Wmax of the first short bead portion 320a is larger than the width 20W (thickness of the plate-like member) of the plate-like member 20 in the short-side direction. Therefore, the full length of the short stop can be made longer than when the total width 320Wmax is equal to or less than the width 20W. As a result, the generation of cracks in the rotary weld 30 can be further suppressed.

(3) In the welded structure 100 according to the present embodiment, the overall width 330Wmax of the first extending bead portion 330a is smaller than the width 20W (thickness of the plate member) of the plate member 20 in the short direction. Therefore, the welding amount can be reduced as compared with the case where the total width 330Wmax is equal to or greater than the width 20W.
(4) In the welded structure 100 according to the present embodiment, in the short direction, the width 330W of the first extending bead portion 330a is smaller the further away from the first short bead portion 320a. Therefore, the amount of welding can be reduced as compared with the case where the width 330W is set uniformly.

  (5) In the welded structure 100 according to the present embodiment, in the longitudinal direction, the length 330L of the first extending bead portion 330a is larger than the length 320L of the first short bead portion 320a. Therefore, the amount of welding can be reduced as compared with the case where the length 330L is equal to or greater than the length 320L.

(6) In the welded structure 100 according to the present embodiment, the extended bead toe angle 330θ formed by the extended bead surface 330S of the first extended bead portion 330a and the base surface 10S of the base member 10 in the longitudinal cross section is: In the short cross section, the longitudinal bead toe angle 310θ formed by the longitudinal bead surface 310S of the first longitudinal bead portion 310a and the base surface 10S of the base member 10 is larger (330θ> 310θ).
Therefore, the extended bead surface 330S and the base surface 10S of the first extended bead portion 330a can be smoothly connected as compared with the case where the extended bead toe angle 330θ is equal to or smaller than the longitudinal bead toe angle 310θ. it can. Therefore, it can suppress that stress concentrates on the boundary of long bead surface 310S and foundation surface 10S among short toes. As a result, the generation of cracks in the turn welded portion 30 can be further suppressed.

(7) In the welded structure 100 according to the present embodiment, the short bead formed by the short bead surface 320S of the first short bead portion 320a and the extended bead surface 330S of the first extended bead portion 330a in the longitudinal cross section. The connection angle 320θ is larger than the longitudinal bead toe angle 310θ (320θ> 310θ).
Accordingly, the short bead surface 320S of the first short bead portion 320a and the extended bead of the first extended bead portion 330a are compared with the case where the short bead coupling angle 320θ is equal to or smaller than the long bead toe angle 310θ. The surface 330S can be smoothly connected. Therefore, it can suppress that stress concentrates on the boundary of the short bead surface 320S and the extended bead surface 330S. As a result, it is possible to suppress the occurrence of a crack starting from the boundary between the short bead surface 320S and the extended bead surface 330S in the rotary weld 30.

(8) In the welded structure 100 according to the present embodiment, the extended bead toe angle 330θ is larger than the short bead coupling angle 320θ, and 330θ>320θ> 310θ is established.
Therefore, the extended bead surface 330S and the base surface 10S of the first extended bead portion 330a can be more smoothly connected as compared with the case where the extended bead toe angle 330θ is equal to or smaller than the short bead coupling angle 320θ. Can do. Therefore, it can suppress more that stress concentrates on the boundary of extended bead surface 330S and foundation face 10S among short toes.

  (9) In the welded structure 100 according to the present embodiment, the turning welded portion 30 is connected to the second short bead portion 320b and extends in the opposite direction to the plate-like member 20 in the longitudinal direction. Part 330b. According to the second extending bead portion 330b, the same effect as that of the first extending bead portion 330a described above can be obtained, so that the welded portion 30 is cracked by turning on both sides in the longitudinal direction of the plate-like member 20. This can be suppressed.

(10) In the method for manufacturing the welded structure 100 according to the present embodiment, the rotating welded portion 30 is formed only by the welding process. Therefore, since it is not necessary to add a process for processing the turning welded part 30 itself, an increase in the manufacturing process can be suppressed.
(11) The manufacturing method of the welded structure 100 according to the present embodiment includes a second extending bead portion forming step. Thus, since the second short bead portion 320b can be formed only by the welding process, an increase in the manufacturing process can be avoided. Moreover, it can suppress that a crack generate | occur | produces in the welding part 30 by turning in the longitudinal direction both sides of the plate-shaped member 20. FIG.

(Other embodiments)
Although the present invention has been described according to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.
(A) In the said embodiment, although the turn welding part 30 decided to have the 2nd short bead part 320b and the 2nd extended bead part 330b, it is not restricted to this. As shown in FIG. 9, when the second side surface 20N ₂ of the plate-like member 20 is in contact with the adjacent member 40, the turning welded portion 30 includes the first longitudinal bead portion 310a and the second longitudinal bead portion 310b. And a first short bead portion 320a and a first extended bead portion 330a. Even in this case, the first extending bead portion 330a can suppress the generation of cracks in the rotating welded portion 30 while suppressing an increase in the manufacturing process.

  (B) In the above embodiment, the planar shape of the first short bead portion 320a is a tapered shape of a type that gradually decreases from the full width 320Wmax as shown in FIG. 4, but is not limited thereto. . The planar shape of the first short bead portion 320a may be an arbitrary taper shape. Specifically, the planar shape of the first short bead portion 320a may be a tapered shape as shown in FIG.

(C) In the above embodiment, the planar shape of the first extending bead portion 330a is a tapered shape having a long section with a predetermined width as shown in FIG. 4, but is not limited thereto. Absent. The planar shape of the first extending bead portion 330a may be a linear shape as shown in FIG. 12 (that is, a substantially rectangular shape).
(D) In the above embodiment, the length 320L of the first short bead portion 320a is smaller than the length 330L of the first extended bead portion 330a, but is not limited thereto. The length 320L of the first short bead portion 320a may be equal to or longer than the length 330L of the first extended bead portion 330a. In this case, since the connection from the first short bead portion 320a to the first extended bead portion 330a can be made smoother, the first short bead portion 320a and the first extended bead portion among the short stop ends. It can suppress more that stress concentrates on the connection point with 330a.

(E) Although the total width 330Wmax of the first extending bead portion 330a is smaller than the width 20W of the plate-like member 20 in the above embodiment, it is not limited to this. The total width 330Wmax may be 20W or less.
(F) In the above embodiment, the relationship of extended bead toe angle 330θ> short bead coupling angle 320θ> long bead toe angle 310θ is established, but the relationship may not be established.

(G) In the above-described embodiment, the turn welded portion 30 is formed by “spot” fillet welding, but is not limited thereto. The rotating weld 30 may be formed by “dent” fillet welding.
(H) Although not particularly mentioned in the above embodiment, a heat affected zone may be formed between the base member 10 and the plate-like member 20 and the turning welded portion 30.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

Hereinafter, examples of the welded structure according to the present invention will be specifically described. However, the present invention is not limited to those shown in the following examples, and may be appropriately changed within the scope not changing the gist thereof. Can be implemented.
(Example)
In accordance with the manufacturing method according to the above embodiment, a welded structure 100a according to an example as shown in FIG. 13 was created.

(Comparative example)
By welding the base member 210 and the plate member 220 uniformly, a welded structure 200a according to a comparative example as shown in FIG. 14 was created. In the welded structure 200a according to the comparative example, the leg width of the turn welded portion 230 was substantially uniform.
(Uniaxial tensile fatigue test)
Next, a uniaxial tensile fatigue test was performed using the welded structure 100a according to the example and the welded structure 200a according to the comparative example.

Specifically, as shown in FIG. 13, a load F along the longitudinal direction is repeatedly applied to the base member 10, and a crack starting from the toe of the rotating welded portion 30 is turned and generated in the welded portion 30. The number of times of load application was counted.
Similarly, as shown in FIG. 14, a load F along the longitudinal direction is repeatedly applied to the base member 10 until a crack starting from the toe of the turning welded portion 230 is turned and is generated in the welded portion 230. The number of load application was counted.

Such a uniaxial tensile fatigue test was performed by dividing the magnitude of the load F into three levels: low level, medium level, and high level. FIG. 15A shows the result when a low level load F is applied. FIG. 15B shows the result when a medium level load F is applied. FIG. 15C shows the result when a high level load F is applied.
As shown in FIGS. 15 (a) to 15 (c), the count number C1 of the welded structure 100a according to the example is the same regardless of whether the magnitude of the load F is low level, medium level, or high level. The number of counts C2 of the welded structure 200a according to the comparative example was four times or more.

  This is because, in the welded structure 100a according to the example, the rotating welded portion 30 includes the first extended bead portion 330a and the second extended bead portion 330b according to the embodiment. Therefore, the effect of the welded structure 100 according to the above embodiment could be confirmed by this uniaxial tensile fatigue test.

100 ... welded structure, 10 ... base member, 10S ... basal surface, 20 ... plate-like member, 20E ... contact portion, 20M ₁ ... first main surface, 20M ₂ ... second main surface, 20 N ₁ ... first side surface 20N ₂ ... 2nd side surface, 30 ... Turn welding part, 40 ... Adjacent member, 310a ... 1st long bead part, 310b ... 2nd long bead part, 320a ... 1st short bead part, 320b ... 2nd short hand Bead part, 321 ... short bead base end part, 322 ... short bead tip end part, 330a ... first extension bead part, 330b ... second extension bead part, 331 ... extension bead base end part, 332 ... extension Bread tip, 330CR ... Crater, 320W ... Width of first short bead portion 320a, 320Wmax ... Full width of first short bead portion 320a, 330W ... Width of first extended bead portion 330a, 330Wmax ... First extension Full width of bead portion 330a 20W: Width (thickness) of the plate-like member 20, 320L: Length of the first short bead portion 320a, 330L: Length of the first extended bead portion 330a, 310θ: Long bead toe angle, 320θ: Short Bead connection angle, 330θ ... extended bead toe angle, S ... weld line, 100a ... welded structure according to example, 200a ... welded structure according to comparative example, 210 ... base member according to comparative example, 220 ... comparison Plate-like member according to example, 230 ... Turn welded part according to comparative example

Claims (13)

A foundation member having a foundation surface;
A first main surface that is erected on the base surface, perpendicular to the base surface, a second main surface that is provided opposite to the first main surface, the first main surface, and the second A plate-like member having a first side surface communicating with the main surface, a second side surface provided opposite to the first side surface, and an abutting portion in contact with the base surface;
A first longitudinal bead portion surrounding the abutting portion of the plate-like member on the base surface and disposed along a longitudinal direction perpendicular to the first side surface on the first main surface; 2nd long bead part arrange | positioned along the said longitudinal direction on 2 main surfaces, and 1st short which is arrange | positioned on the said 1st side surface, and is connected with the said 1st long bead part and the said 2nd long bead part. A turn welded portion having a hand bead portion and a first extending bead portion connected to the first short bead portion and extending in the longitudinal direction in the direction opposite to the plate-like member;
With
In the short direction intersecting with the longitudinal direction, the width of the first short bead portion decreases as the distance from the plate member increases.
In the short direction, the full width of the first extended bead portion is smaller than the full width of the first short bead portion,
Welded structure. In the short direction, the full width of the first short bead portion is larger than the thickness of the plate-like member.
The welded structure according to claim 1. In the short direction, the full width of the first extending bead portion is smaller than the thickness of the plate-shaped member.
The welded structure according to claim 1 or 2. In the short direction, the width of the first extended bead portion is smaller as it is farther from the first short bead portion,
The welded structure according to any one of claims 1 to 3. In the longitudinal direction, the length of the first extending bead portion is larger than the length of the first short bead portion,
The welded structure according to any one of claims 1 to 4. In the longitudinal direction, the length of the first extending bead portion is smaller than the length of the first short bead portion,
The welded structure according to any one of claims 1 to 4. An extended bead toe angle formed by the surface of the first extended bead portion and the base surface in a longitudinal section perpendicular to the base surface and the first side surface is perpendicular to the base surface and the first main surface. In a short cross-section, it is larger than the longitudinal bead toe angle formed by the surface of the first longitudinal bead portion and the base surface,
The welded structure according to any one of claims 1 to 6. The short bead connection angle formed by the surface of the first extended bead part and the surface of the first short bead part in the longitudinal cross section is larger than the long bead toe angle,
The welded structure according to claim 7. The extended bead toe angle is larger than the short bead coupling angle,
The welded structure according to claim 8. The rotating weld is
A second short bead portion disposed on the second side surface and connected to the first long bead portion and the second long bead portion;
A second extending bead portion connected to the second short bead portion and extending in the longitudinal direction opposite to the plate-like member;
Having
The welded structure according to any one of claims 1 to 9. On the base surface of the base member, a first main surface perpendicular to the base surface, a second main surface provided opposite to the first main surface, the first main surface, and the second main surface An erecting step of erecting a plate-like member having a first side surface communicating with the second side surface provided opposite to the first side surface;
After welding the boundary between the first side surface and the base surface, the welding is performed along the longitudinal direction while gradually reducing the welding width in the short direction intersecting the longitudinal direction perpendicular to the first side surface. A short bead portion forming step;
A first extending bead portion forming step of welding straight from the first short bead portion along the longitudinal direction;
A first longitudinal bead portion forming step of welding a boundary between the first main surface and the base surface;
A second longitudinal bead forming step of welding a boundary between the second main surface and the base surface;
Comprising
Manufacturing method of welded structure. A second short bead portion forming step of welding a boundary between the second side surface and the base surface;
After the second short bead portion forming step, a second extended bead portion forming step of welding straight from the second short bead portion in the longitudinal direction;
Comprising
The manufacturing method of the welded structure of Claim 11. The first longitudinal bead portion forming step and the second longitudinal bead portion forming step are performed after the first extending bead portion forming step.
The manufacturing method of the welded structure of Claim 11 or 12.

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