JP2008050807A - Welded structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welded structure which is enhanced in connection strength between one member and the other member welded to each other. <P>SOLUTION: In the welded structure, fillet weld portions 17 are formed in a gap between a left web 12A of a square cylinder body 12 and a reinforcing plate 16, and a gap between a right web 12B and the reinforcing plate 16, and a plurality of deeply penetrated weld portions 18 are formed so as to intersect each fillet weld portion 17. Thus the fillet weld portion 17 can be reinforced by deeply penetrated weld portions 18, and therefore the connection strength between the square cylinder body 12 and the reinforcing plates 16 is enhanced. Further, smooth bead toes 18A, 18B by the deeply penetrated weld portion 18 are formed at locations at which the fillet weld portion 17 and the deeply penetrated weld portions 18 intersect each other, and therefore the connection strength between the square cylinder body 12 and the reinforcing plates 16 is further enhanced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a welded structure suitably used for a construction machine structure such as a boom and an arm of a hydraulic excavator, for example.

  Generally, a hydraulic excavator as a construction machine is provided with a self-propelled lower traveling body, an upper revolving body mounted on the lower traveling body so as to be capable of swiveling, and an upside-down movable structure on the front side of the upper revolving body. It is roughly constituted by the working device.

  In addition, the excavator working device generally includes a boom whose base end side is rotatably attached to the turning frame of the upper swing body, an arm rotatably attached to the distal end side of the boom, It is composed of a working tool such as a bucket that is rotatably attached to the tip side, and performs soil excavation work and the like.

  The arm used in the working device of the hydraulic excavator described above includes a hollow rectangular cylinder surrounded by the left and right webs and upper and lower flanges, and shafts on the left and right webs of the rectangular cylinder. A cylindrical boom boss that is fixed at both ends in the direction and is pivotally connected to the tip of the boom, and fixed to the left and right webs of the rectangular tube to reinforce the periphery of the boom boss It is comprised as a welding structure provided with the reinforcement board (for example, refer patent document 1).

JP 2003-268804 A

  Here, the arm by the prior art mentioned above is set as the structure which provides a fillet weld part and a deep penetration weld part between the left and right webs which comprise a square cylinder, and a reinforcement board. In this case, the fillet weld is formed by performing fillet welding on the corner between the peripheral edge of the reinforcing plate and the web using means such as arc welding, and the deep penetration weld is, for example, It is formed by melting the reinforcing plate and the web in the thickness direction using means such as laser welding.

  As described above, since the fillet weld and the deep penetration weld are formed between the web of the rectangular tube and the reinforcing plate, the welded portion between the rectangular tube and the reinforcing plate is increased. The bonding strength between the reinforcing plate and the reinforcing plate can be increased.

  However, in the above-described prior art, the bead toe portion of the fillet welded portion formed between the web of the rectangular tube and the end edge portion of the reinforcing plate may protrude with a large step from the surface of the web. . As described above, when a steep step is formed at the boundary between the bead toe and the surface of the web, stress concentrates on the step so that the square tube body starts from the bead toe. There is a problem that the web and the reinforcing plate are easily cracked, and the bonding strength between the rectangular tube and the reinforcing plate is lowered.

  In contrast, by grinding the bead toe of the fillet weld using a grinder or the like, and forming the bead toe so as to be smoothly continuous with the web surface, Bonding strength can be increased. However, in this case, a great amount of time and labor are required for the operation of smoothly grinding the bead toe, resulting in a problem that workability is reduced.

  The present invention has been made in view of the above-described problems of the prior art, and provides a welded structure that can increase the joining strength between one side member and the other side member joined by fillet welding. It is aimed.

  In order to solve the above-described problems, the present invention has a one-side member and another member joined to the one-side member, and is formed by joining the one-side member and the other-side member by fillet welding. Applies to structures.

  The feature of the configuration adopted by the invention of claim 1 is that the thickness of the fillet welded portion is thicker than the one side member and the other side member in a state intersecting with the fillet welded portion. A plurality of deep penetration welds to be melted in the direction are provided.

  The invention of claim 2 is that each of the deep penetration welds is provided in a direction orthogonal to the welding direction of the fillet welds.

  According to a third aspect of the present invention, the one side member is formed by being surrounded by left and right webs and upper and lower flanges, and is provided with a boom boss that is rotatably attached to a boom of a construction machine. A square tube of a mechanical arm, and the other side member is a reinforcing plate fixed to a web of the square tube to reinforce the periphery of the boom boss, and the web of the square tube and the reinforcement The plate is joined by fillet welding, and each deep penetration welded portion intersects with the fillet welded portion and extends from the boom boss along the direction of the main stress acting on the rectangular tube body. It is to have done.

  According to the first aspect of the present invention, a plurality of deep penetration welds are provided between the one side member and the other side member in a state intersecting with the fillet weld portion that joins between the one side member and the other side member. By forming, a fillet weld can be reinforced by each of these deep penetration welds. Moreover, since the welding part of one side member and an other side member can be ensured largely, the joint strength of one side member and an other side member can be raised.

  In addition, each deep penetration weld intersects with the fillet weld, so that the weld bead of the fillet weld can be melted together with the one side member and the other side member, and the deep weld with the fillet weld. A smooth bead toe can be formed by a deep penetration weld at the location where the weld intersects. As a result, it is possible to prevent the one-side member and the other-side member from cracking starting from the bead toes, and the bonding strength between the one-side member and the other-side member can be further increased. In addition, workability when the one side member and the other side member are joined can be improved because the bead toe portion need not be formed smoothly using a grinder or the like.

  According to the invention of claim 2, even if a stress is applied to the fillet weld formed between the one side member and the other side member, for example, in a direction orthogonal to the welding direction, the stress is absorbed. Since it can receive reliably by each deep penetration weld part which cross | intersects a meat weld part, the joint strength of one side member and another side member can be raised.

  According to the invention of claim 3, by providing the fillet welded portion and the plurality of deep penetration welded portions between the web of the rectangular tube and the reinforcing plate, the welded portion between the rectangular tube and the reinforcing plate is enlarged. Since it can ensure, the joint strength of a square cylinder and a reinforcement board can be raised. Moreover, even if the main stress acts on the rectangular tube body from the boom boss by providing a plurality of deep penetration welds so as to extend along the direction of the main stress acting on the rectangular tube body from the boom boss, This stress can be reliably received by each deep penetration weld. As a result, it is possible to prevent cracks in the rectangular tube body and the reinforcing plate starting from the toe portion of the deep penetration welded portion, and it is possible to increase the strength of the entire construction machine arm composed of the rectangular tube body, the reinforcing plate, and the like. .

  Hereinafter, the embodiment of the welded structure according to the present invention will be described in detail with reference to FIG. 1 to FIG. 16 by taking as an example the case where it is applied to a member constituting a hydraulic excavator.

  First, FIGS. 1 to 5 show a first embodiment of the present invention. In this embodiment, an arm of a hydraulic excavator is taken as an example.

  In the figure, reference numeral 1 denotes a hydraulic excavator. The hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2, an upper revolving body 3 that is turnably mounted on the lower traveling body 2, and the upper swivel. The working device 4 is provided on the front side of the body 3 so as to be able to move up and down. The working device 4 is used for excavating soil and the like.

  Here, the working device 4 includes a later-described boom 21 whose base end is rotatably attached to the upper swing body 3, an after-mentioned arm 11 rotatably attached to the distal end side of the boom 21, A bucket 41, which will be described later, is rotatably attached to the distal end side of the arm 11, and a boom cylinder 5, an arm cylinder 6, and a bucket cylinder 7.

  Reference numeral 11 denotes an arm as a welded structure according to the present embodiment. The arm 11 is attached to the tip side of the boom 21 so as to be rotatable. As shown in FIGS. 2 to 5, the arm 11 includes a rectangular tube 12, a boom boss 13, a bucket boss 14, a cylinder bracket 15, a reinforcing plate 16, and the like, which will be described later.

  Reference numeral 12 denotes a rectangular tube constituting the main body of the arm 11, and the rectangular tube 12 constitutes one side member to which a later-described reinforcing plate 16 is welded. Here, the rectangular cylinder 12 includes a left web 12A and a right web 12B facing in the left and right directions, and an upper flange 12C and a lower flange facing in the upper and lower directions across the left and right webs 12A and 12B. 12D is welded to form a square cylinder with a square cross section. A flat base end plate 12E is fixed to the base end portion of the rectangular tube body 12 by welding, and the base end side of the square tube body 12 is closed by the base end plate 12E.

  Reference numeral 13 denotes a boom boss provided at a corner between the lower flange 12D of the rectangular tube body 12 and the proximal end plate 12E. The boom boss 13 is rotatable to the distal end side of the boom 21. It is pin-coupled (see FIG. 1). The boom boss 13 is made of a cylindrical body, and both end sides in the axial direction are welded to the left and right webs 12A and 12B of the rectangular tube body 12, and the outer peripheral surface is attached to the lower flange 12D and the proximal end plate 12E. Welded.

  Reference numeral 14 denotes a bucket boss provided on the tip end side of the rectangular tube body 12, and the bucket boss 14 is pin-coupled so that the bucket 41 can rotate. The bucket boss 14 is made of a cylindrical body, and both end sides in the axial direction are welded to the left and right webs 12A and 12B of the rectangular tube body 12, and the outer peripheral surface is at the tip of the upper flange 12C and the lower flange 12D. Welded.

  Reference numeral 15 denotes a cylinder bracket provided on the base end side of the rectangular tube body 12, and the cylinder bracket 15 is constituted by a pair of plates facing each other in the left and right directions. It is fixed to the side end plate 12E by means such as welding. The cylinder bracket 15 is configured such that the distal end side of the arm cylinder 6 is pivotally coupled to the cylinder bracket 15 and the proximal end side of the bucket cylinder 7 is pivotally coupled to the cylinder bracket 15.

  Reference numeral 16 denotes left and right reinforcing plates (only one is shown) welded to the left and right webs 12A and 12B of the rectangular cylinder 12 to reinforce the periphery of the boom boss 13. The reinforcing plate 16 is on one side. The other side member is constituted with respect to the rectangular tube body 12 as a member.

  Here, as shown in FIGS. 3 and 4, the reinforcing plate 16 includes a concave curved portion 16 </ b> A that is curved in an arc shape so as to surround the outer peripheral edge portion of the boom boss 13, and a lower flange 12 </ b> D of the rectangular tube body 12. A front wall portion 16B extending from the concave curved portion 16A to the front wall portion 16B along the lower flange 12D, and a proximal side end plate 12E. And is formed as a mountain-shaped plate body having the other side wall portion 16D extending from the concave curved portion 16A to the front wall portion 16B, and is firmly fixed to the web 12A by welding. As shown in FIGS. 4 and 5, a fillet weld portion 17 described later and a plurality of deep penetration weld portions 18 are provided between the web 12 </ b> A of the rectangular tube 12 and the reinforcing plate 16. Yes.

  17 is a fillet welded portion provided between the rectangular tube 12 (web 12A) as one side member and the reinforcing plate 16 as the other side member. The fillet welded portion 17 is shown in FIGS. As shown in FIG. 5, the fillet weld is formed between the surface of the web 12A and the edge of the reinforcing plate 16 by means of, for example, arc welding. The fillet weld portion 17 forms a weld bead portion that continues over the entire circumference of the reinforcing plate 16.

  18, 18,... Are a plurality of deep penetration welds provided between the web 12A of the rectangular tube 12 (one side member) and the reinforcing plate 16 (the other side member) separately from the fillet welds 17. As shown in FIG. 4, each deep penetration weld 18 intersects with the fillet weld 17 provided from one side wall 16 </ b> C to the other side wall 16 </ b> D of the reinforcing plate 16. It is formed at a plurality of locations at appropriate intervals in the welding direction of the welded portion 17. Each deep penetration weld 18 cooperates with the fillet weld 17 to firmly fix the reinforcing plate 16 to the surface of the web 12A.

  Here, as shown in FIG. 4 and FIG. 5, each deep penetration weld 18 uses an intermediate thickness of the web 12 </ b> A from the surface of the reinforcing plate 16 using deep penetration welding with high energy density such as laser welding. It is formed by melting up to the part in the plate thickness direction. Each deep penetration weld 18 extends linearly from the vicinity of the front wall 16 </ b> B to the web 12 </ b> A in the reinforcing plate 16, and the midway thereof intersects the fillet weld 17.

  In this case, when the arm 11 is operated during excavation work, as shown by an arrow F in FIG. 3, main stress acts on the rectangular cylinder 12 in a direction extending radially from the boom boss 13. On the other hand, the deep penetration welds 18 are arranged so as to spread radially around the boom boss 13 and extend along the direction of the main stress acting around the boom boss 13.

  As shown in FIG. 5, the deep penetration welded portion 18 includes one bead toe portion 18A located in the vicinity of the fillet weld portion 17 in the reinforcing plate 16 and the fillet weld portion 17 in the web 12A. It extends linearly with the other bead toe 18B located in the vicinity, and is deeply melted from the surface of the reinforcing plate 16 to the intermediate portion in the thickness direction of the web 12A.

  In this case, since the deep penetration welding when forming the deep penetration welded portion 18 has a high energy density, not only the reinforcing plate 16 and the web 12A are melted but also the weld bead of the fillet welded portion 17 is melted. be able to. As a result, a bead stop 18A that smoothly continues from the surface of the reinforcing plate 16 and a bead stop that smoothly continues from the surface of the web 12A are provided at the portion where the fillet weld 17 and the deep penetration weld 18 intersect. A deep penetration weld 18 having an end 18B can be formed, and cracks can be prevented from occurring in the web 12A, the reinforcing plate 16 and the like starting from the bead toes 18A and 18B of the deep penetration weld 18. It has a configuration.

  Further, since the deep penetration welding when forming the deep penetration weld 18 can increase the welding speed as compared with, for example, arc welding, the amount of heat input to the reinforcing plate 16 and the web 12A to be welded is correspondingly increased. Can be lowered. For this reason, the weld bead part (weld metal) of each deep penetration weld part 18 becomes a structure hardened rather than a base material (reinforcement board 16, web 12A) by rapid heating and rapid cooling.

  The arm 11 as a welded structure according to the present embodiment has the above-described configuration, and is provided between the surfaces of the left and right webs 12A and 12B constituting the rectangular tube 12 and the edge of the reinforcing plate 16. In addition to forming the fillet weld portion 17, a plurality of deep penetration weld portions 18 are provided that allow the webs 12 </ b> A and 12 </ b> B and the reinforcing plate 16 to be melted in the plate thickness direction while intersecting with the fillet weld portion 17. Yes.

  As a result, the fillet welds 17 formed between the web 12A of the rectangular cylinder 12 and the reinforcing plate 16 can be reinforced by the plurality of deep penetration welds 18, and each deep penetration weld 18 can be reinforced. Since the welded portion between the web 12A and the reinforcing plate 16 can be increased by the amount provided, the bonding strength between the rectangular tube body 12 and the reinforcing plate 16 can be increased.

  Further, the leg length of the fillet welded portion 17 can be shortened by increasing the bonding strength between the web 12 </ b> A of the rectangular tube 12 and the reinforcing plate 16. As a result, when performing fillet welding between the web 12A and the edge of the reinforcing plate 16, the welding time can be shortened, and the workability of the welding operation can be improved. Moreover, since the leg length of the fillet welded portion 17 can be shortened, the thickness of the reinforcing plate 16 can be reduced (thin), so that the weight of the entire arm 11 can be reduced and the manufacturing cost can be reduced. Can also contribute.

  In addition, by crossing each deep penetration weld 18 with the fillet weld 17, not only is the web 12 A and the reinforcement plate 16 melted when deep penetration welding is performed on the web 12 A and the reinforcement plate 16, The weld bead of the fillet weld portion 17 can also be melted. Thereby, the smooth bead toes 18A and 18B by the deep penetration weld 18 can be formed at the portion where the fillet weld 17 and the deep penetration weld 18 intersect, and these bead toes 18A. , 18B as a starting point, it is possible to prevent the web 12A, the reinforcing plate 16 and the like from cracking.

  As a result, the bonding strength between the rectangular tube 12 and the reinforcing plate 16 can be increased, and the durability of the arm 11 can be increased. Further, since it is not necessary to form the bead toe portions 18A and 18B smoothly using a grinder or the like, the workability when joining the rectangular tube body 12 and the reinforcing plate 16 can be improved.

  Further, since a plurality of deep penetration welds 18 are provided at intervals in the welding direction of the fillet welds 17, the bead toe portions 18A and 18B of the deep penetration welds 18 that are smoothly continuous are formed at a plurality of locations. Thus, the bonding strength between the rectangular tube 12 and the reinforcing plate 16 can be further increased.

  Further, each deep penetration weld 18 extends from the boom boss 13 along the direction of the main stress acting on the rectangular tube 12 when the arm 11 is operated (the direction indicated by the arrow F in FIG. 3). It is formed radially with the boss 13 as the center. For this reason, even when a main stress is applied radially from the boom boss 13 to the square cylinder 12 when an external stress is applied to the arm 11 due to excavation work or the like of the work device 4, The direction and the welding direction of the deep penetration weld 18 can be matched. Thereby, stress acting on the bead toes 18A and 18B of the deep penetration weld 18 shown in FIG. 5 can be relieved, so that the rectangular tube 12 and the reinforcing plate are started from these bead toes 18A and 18B. It is possible to reliably prevent cracks from occurring in the arm 16 and increase the strength of the arm 11 as a whole.

  Next, FIG. 6 to FIG. 12 show a second embodiment of the present invention. In this embodiment, a boom of a hydraulic excavator is taken as an example of a welded structure.

  In the figure, 21 is a boom as a welded structure according to the present embodiment, and the boom 21 is attached to the upper swing body 3 of the excavator 1 so as to be rotatable. As shown in FIG. 6, the boom 21 includes a rectangular tube body 22, a proximal end boss 23, a reinforcing plate 26, an arm mounting bracket 29, and the like, which will be described later.

  Reference numeral 22 denotes a rectangular tube constituting the main body of the boom 21, and the rectangular tube 22 constitutes one side member to which a base end side boss 23, a reinforcing plate 26, and an arm mounting bracket 29 described later are welded. is there. Here, the rectangular tube 22 is formed as an elongated hollow structure that is curved in a substantially “<” shape as a whole. The rectangular tube 22 has a left web 22A and a right web 22B that face in the left and right directions, and an upper flange 22C and a lower flange 22D that face in the upper and lower directions across the left and right webs 22A and 22B. Are formed into a square tube shape having a quadrangular cross section.

  23 is a base end side boss welded to the base end side of the rectangular tube body 22, and the base end side boss 23 constitutes the other side member with respect to the square tube body 22 as one side member. The revolving body 3 is pin-coupled so as to be rotatable. The proximal end boss 23 is formed of a hollow cylindrical body, and the outer peripheral side of the proximal end boss has an upper flange 22C and a lower flange 22D of the rectangular tube body 22 by a fillet weld portion 24 and a deep penetration weld portion 25 described later. To be welded.

  Reference numeral 24 denotes a fillet welded portion provided between the rectangular tube 22 as one side member and the proximal end boss 23 as the other side member. The fillet welded portion 24 is shown in FIGS. 7 and 8. As described above, between the end edge portion of the upper flange 22 </ b> C and the outer peripheral surface of the proximal end boss 23 constituting the rectangular tube body 22, and between the end edge portion of the lower flange 22 </ b> D and the outer peripheral surface of the proximal end boss 23. And are formed respectively. The fillet weld portion 24 forms a weld bead portion that is linearly continuous along the axial direction of the proximal end boss 23.

  25, 25,... Between the upper flange 22C and the proximal end boss 23 of the rectangular tube 22 and the lower flange 22D of the rectangular tube 22 and the proximal boss 23 in a state of intersecting with the fillet weld portion 24. A plurality of deep penetration welds 25 are provided between the plurality of deep penetration welds 25 at appropriate intervals in the welding direction of the fillet welds 24. Each deep penetration welded portion 25 cooperates with the fillet welded portion 24 to firmly fix the upper and lower flanges 22C and 22D and the proximal end boss 23 together.

  Here, as shown in FIGS. 7 and 8, each deep penetration weld 25 is formed by causing the upper and lower flanges 22 </ b> C and 22 </ b> D and the proximal end boss 23 to melt in the plate thickness direction. . Each deep penetration weld 25 extends linearly from the upper flange 22C to the proximal end boss 23 and from the lower flange 22D to the proximal end boss 23, and the intermediate portion is a fillet weld. Crosses 24.

  As a result, smooth bead toes 25A and 25B formed by the deep penetration weld 25 are formed at the portion where the fillet weld 24 and the deep penetration weld 25 intersect, and these bead toes 25A and 25B are formed. As a starting point, the upper and lower flanges 22C and 22D, the base end side boss 23 and the like of the rectangular tube body 22 can be prevented from cracking.

  Further, as shown in FIG. 7, each deep penetration weld 25 is formed to extend in a direction perpendicular to the welding direction of the fillet weld 24. For this reason, for example, even if a stress is applied to the fillet welded portion 24 in a direction perpendicular to the welding direction due to a tensile load or the like acting on the rectangular tube 22, this stress is applied to the fillet welded portion 24. It is the structure which can receive reliably by each cross penetration weld part 25 which cross | intersects.

  26 and 26 are left and right reinforcing plates which are welded to the left and right webs 22 </ b> A and 22 </ b> B and are located on the proximal end side of the rectangular tube body 22, and the reinforcing plates 26 are arranged around the proximal boss 23. The other side member is configured with respect to the rectangular tube 22 as one side member.

  Here, as shown in FIGS. 9 and 10, the reinforcing plate 26 is a flat plate having a concave curved portion 26A that is curved in a substantially V shape between the upper and lower flanges 22C and 22D of the rectangular tube body 22, The square cylinder 22 is firmly fixed to the left and right webs 22A and 22B by welding. Between the left and right webs 22A and 22B and the concave curved portion 26A of the reinforcing plate 26, a fillet weld portion 27 and a deep penetration weld portion 28, which will be described later, are provided.

  Reference numeral 27 denotes a fillet weld portion provided between the rectangular tube body 22 as one side member and the reinforcing plate 26 as the other side member. It is formed between the surface of the right webs 22 </ b> A and 22 </ b> B and the edge of the concave curved portion 26 </ b> A of the reinforcing plate 26. The fillet weld portion 27 forms a continuous weld bead portion along the curved shape of the concave curved portion 26A.

  28, 28,... Between the left web 22A and the reinforcing plate 26 of the rectangular tube 22 and between the right web 22B and the proximal boss 23 of the rectangular tube 22 while intersecting the fillet weld 27. A plurality of deep penetration welds provided are provided at a suitable interval in the welding direction of the fillet welds 27 provided along the concave curved portions 26A of the reinforcing plate 26. It has been.

  Here, as shown in FIGS. 9 and 10, each deep penetration weld 28 is formed between the vicinity of the concave curved portion 26 </ b> A of the reinforcing plate 26 and the left web 22 </ b> A of the rectangular tube 22 and the reinforcing plate 26. Among them, the portion extending in the vicinity of the concave curved portion 26 </ b> A and the right web 22 </ b> B of the rectangular tube body 22 extend linearly, and the intermediate portion intersects the fillet weld portion 27.

  As a result, smooth bead toes 28A and 28B are formed by the deep penetration weld 28 at the intersection of the fillet weld 27 and the deep penetration weld 28, and these bead toes 28A and 28B. Is used to prevent the left and right webs 22A and 22B, the reinforcing plate 26 and the like of the rectangular tube body 22 from cracking.

  Each deep penetration weld 28 is formed to extend in a direction orthogonal to the welding direction of the fillet weld 27, and stress is applied to the fillet weld 27 in a direction orthogonal to the weld direction. However, this stress can be reliably received by each deep penetration weld 28.

  Reference numerals 29 and 29 denote left and right arm mounting brackets welded to the distal end side of the rectangular tube body 22. These left and right arm mounting brackets 29 are members on the other side of the rectangular tube body 22 as one side member. The arm 11 is pin-coupled so as to be rotatable. Here, as shown in FIGS. 11 and 12, each arm mounting bracket 29 is formed of a substantially triangular flat plate as a whole, and a concave curved portion 29 </ b> A curved in a substantially V shape is provided on the base end side thereof. In addition, a pin insertion hole 29B is provided on the tip side.

  The arm mounting bracket 29 is firmly fixed to the distal end side of the rectangular tube body 22 by welding, and between the left web 22A of the rectangular tube body 22 and the arm mounting bracket 29 and the right web 22B of the rectangular tube body 22. Between the arm mounting bracket 29, a fillet welded portion 30 and a deep penetration welded portion 31, which will be described later, are provided.

  Reference numeral 30 denotes a fillet weld portion provided between the rectangular tube body 22 as one side member and an arm mounting bracket 29 as the other side member. The fillet weld portion 30 is a left portion constituting the square tube body 22. , Formed between the surface of the right webs 22A, 22B and the edge of the concave curved portion 29A of the arm mounting bracket 29, forming a continuous weld bead portion along the curved shape of the concave curved portion 29A. ing.

  31, 31,... Between the left web 22 </ b> A of the rectangular tube 22 and the arm mounting bracket 29, and between the right web 22 </ b> B of the rectangular tube 22 and the arm mounting bracket 29 in a state of intersecting the fillet weld 30. Among the plurality of deep penetration welds provided, a plurality of each of these deep penetration welds 31 are provided at an appropriate interval in the welding direction of the fillet weld 30 provided along the concave curved portion 29A of the arm mounting bracket 29. Is provided.

  Here, each deep penetration weld 31 is between the vicinity of the concave curved portion 29 </ b> A of the arm mounting bracket 29 and the left web 22 </ b> A of the rectangular tube 22, and near the concave curved portion 29 </ b> A of the arm mounting bracket 29. The portion extends linearly between the portion and the right web 22 </ b> B of the rectangular tube 22, and the portion in the middle intersects the fillet weld portion 30.

  As a result, smooth bead toes 31A and 31B formed by the deep penetration weld 31 are formed at the intersections of the fillet weld 30 and the deep penetration weld 31. The bead toes 31A and 31B are As a starting point, the left and right webs 22A and 22B of the rectangular tube body 22, the arm mounting bracket 29, and the like can be prevented from cracking.

  Each deep penetration weld 31 is formed to extend in a direction orthogonal to the welding direction of the fillet weld 30 and stress is applied to the fillet weld 30 in a direction orthogonal to the weld direction. However, this stress can be reliably received by each deep penetration weld 31.

  The boom 21 as a welded structure according to the present embodiment has the above-described configuration, and fillet welding is performed between the upper and lower flanges 22C and 22D and the proximal end boss 23 constituting the rectangular tube body 22. While forming the part 24, the deep penetration weld part 25 which cross | intersects this fillet weld part 24 is formed. Thereby, the smooth bead toe portions 25A and 25B by the deep penetration welded portion 25 can be formed at a portion where the fillet welded portion 24 and the deep penetration welded portion 25 intersect with each other. Bonding strength with the side boss 23 can be increased.

  Further, by forming a fillet weld portion 27 and a deep penetration weld portion 28 between the left and right webs 22A and 22B constituting the rectangular tube body 22 and the reinforcing plate 26, the fillet weld portion 27 and Smooth bead toe portions 28A and 28B can be formed at a portion where the deep penetration weld 28 intersects, and the bonding strength between the rectangular tube body 22 and the reinforcing plate 26 can be increased.

  Further, by forming a fillet welded portion 30 and a deep penetration welded portion 31 between the left and right webs 22A and 22B constituting the rectangular tube body 22 and the arm mounting bracket 29, the fillet welded portion 30 is formed. Smooth bead toe portions 31A and 31B can be formed at portions where the deep penetration welded portion 31 intersects, and the bonding strength between the rectangular tube body 22 and the arm mounting bracket 29 can be increased.

  Next, FIGS. 13 and 14 show a third embodiment of the present invention. In this embodiment, a bucket of a hydraulic excavator is taken as an example of a welded structure.

  In the figure, reference numeral 41 denotes a bucket as a welded structure according to the present embodiment. The bucket 41 is pivotally attached to the distal end side of the arm 11 and excavates earth and sand. The bucket 41 includes a bottom plate 42, a left side plate 44, a right side plate 45, a left side edge 46, a right side edge 47, a cutting edge 48, a bottom plate reinforcing plate 50, a side plate reinforcing plate 53 and the like which will be described later.

  Reference numeral 42 denotes a bottom plate of the bucket 41. The bottom plate 42 is formed as a plate body whose upper and lower portions are curved in an arc shape by bending a steel plate or the like. The left and right mounting brackets 43 and 43 are fixedly provided on the upper end side of the bottom plate 42, and each mounting bracket 43 is pivotally connected to the distal end side of the arm 11. ing. Here, the bottom plate 42 constitutes one side member to which a below-described bottom plate reinforcing plate 50 is welded.

  44 is a left side plate fixed to the left end portion of the bottom plate 42, 45 is a right side plate fixed to the right end portion of the bottom plate 42, and the left and right side plates 44, 45 are welded to a side plate reinforcing plate 53 described later. It constitutes one side member. Here, the left and right side plates 44 and 45 are substantially triangular plates, facing each other in the left and right directions with the bottom plate 42 interposed therebetween, so that a space for storing earth and sand or the like is formed between the bottom plate 42 and the left and right side plates 44 and 45. To form.

  A left side edge 46 extends upward and downward on the opening side of the left side plate 44 opposite to the bottom plate 42, and a right side edge 47 extends upward on the opening side of the right side plate 45. , Extending downward.

  Reference numeral 48 denotes a cutting edge provided on the lower end side of the bottom plate 42. The cutting edge 48 is formed of a thick plate body, for example, by the bottom plate 42, and the lower ends of the bottom plate 42 and the lower ends of the left and right side edges 46, 47. It is fixed to the part or the like by welding or the like and extends in the left and right directions. A plurality of excavating claws 49 are attached to the cutting edge 48 side by side in the left and right directions.

  50, 50,... Are a plurality of bottom plate reinforcing plates welded to the outer surface of the bottom plate 42. Each bottom plate reinforcing plate 50 constitutes the other side member with respect to the bottom plate 42 as one side member. Here, the bottom plate reinforcing plate 50 is formed of a rectangular flat plate curved corresponding to the curved shape of the bottom plate 42, and is fixed to the bottom plate 42 by welding.

  Reference numeral 51 denotes a fillet welded portion provided between a bottom plate 42 as one side member and a bottom plate reinforcing plate 50 as the other side member. The fillet welded portion 51 includes the outer surface of the bottom plate 42 and the bottom plate reinforcing plate 50. The weld bead portion is formed along the outer peripheral edge of the bottom plate reinforcing plate 50.

  52, 52,... Are a plurality of deep penetration welds provided between the bottom plate 42 and the bottom plate reinforcing plate 50 in a state of intersecting with the fillet welds 51. Each of these deep penetration welds 52 is a fillet weld. A plurality of 51 are provided at appropriate intervals in the welding direction. Each deep penetration weld 52 extends linearly from the peripheral edge of the bottom plate reinforcing plate 50 to the bottom plate 42, and the intermediate portion intersects the fillet weld 51 in a direction perpendicular to the welding direction. Yes.

  53 is a side plate reinforcing plate welded to the outer surface of the left and right left side plates 44, 45. The side plate reinforcing plate 53 is provided with an other side member with respect to the left and right side plates 44, 45 as one side member. It constitutes. Here, the side plate reinforcing plate 53 is a flat plate having a substantially rectangular shape, and is fixed to the range from the upper and lower intermediate portions of the left and right side plates 44 and 45 to the lower end side by welding.

  54 is a fillet welded portion provided between the left and right side plates 44 and 45 serving as one side member and a side plate reinforcing plate 53 serving as the other side member. It is formed between the outer side surface and the edge of the side plate reinforcing plate 53, and is formed between the outer surface of the right side plate 45 and the edge of the side plate reinforcing plate 53.

  55, 55,... Are a plurality of deep penetration welds provided between the left and right side plates 44, 45 and the side plate reinforcing plate 53 in a state of intersecting with the fillet welds 54. Are provided with an appropriate interval in the welding direction of the fillet weld 54. Each deep penetration weld 55 intersects the fillet weld 54 in a direction perpendicular to the welding direction.

  The bucket 41 as a welded structure according to the present embodiment has the above-described configuration, and forms a fillet weld 51 between the bottom plate 42 and the bottom plate reinforcing plate 50, and the fillet weld 51 By forming the intersecting deep penetration welds 52, the bonding strength between the bottom plate 42 and the bottom plate reinforcing plate 50 can be increased. Further, a fillet weld 54 is formed between the left and right side plates 44, 45 and the side plate reinforcing plate 53, and a deep penetration weld 55 that intersects the fillet weld 54 is formed, so that the left The bonding strength between the right side plates 44 and 45 and the side plate reinforcing plate 53 can be increased.

  In the first embodiment described above, the left web 12A and the reinforcing plate 16 of the rectangular tube 12 intersect the fillet welded portion 17 and act on the rectangular tube 12 from the boom boss 13. The case where the some deep penetration weld part 18 extended along the direction of main stress is illustrated.

  However, the present invention is not limited to this, and a plurality of deep penetration welds 61 extending in a direction orthogonal to the welding direction of the fillet welds 17 may be provided, for example, as in a modification shown in FIG. .

  Further, in the second embodiment described above, a fillet weld portion 24 and a plurality of deep penetration weld portions 25 are provided between the rectangular tube body 22 and the proximal end boss 23 constituting the boom 21, The case where it is set as the structure extended in the direction orthogonal to the welding direction of the fillet weld part 24 is illustrated as the deep penetration weld part 25. FIG.

  However, the present invention is not limited to this, and a plurality of deep penetration welds 62 extending in a direction inclined with respect to the welding direction of the fillet welds 24 are provided as in another modification shown in FIG. It is good also as a structure. In this case, since the weld length of each deep penetration weld 62 can be increased by the amount inclined with respect to the welding direction of the fillet weld 24, the rectangular tube 22 and the proximal end boss 23 Therefore, it is possible to secure a larger welded portion and to increase the bonding strength between the two.

  In the first embodiment described above, the fillet welded portion 17 and the deep penetration welded portion are joined to the joint portion between the left and right webs 12A and 12B of the rectangular tube body 12 constituting the arm 11 and the reinforcing plate 16. 18 is formed. However, the present invention is not limited to this. For example, the joined portion between the left and right webs 12A and 12B and the upper flange 12C of the rectangular cylinder 12, and the joined portion between the left and right webs 12A and 12B and the lower flange 12D. It is good also as a structure which forms a fillet weld part and a deep penetration weld part in a part.

  Furthermore, the welded structure according to the present invention is not limited to the arm 11 according to the first embodiment, the boom 21 according to the second embodiment, and the bucket 41 according to the third embodiment, but is joined by welding. The present invention can be widely applied to a welded structure including one side member and another side member.

It is a front view showing a hydraulic excavator provided with an arm as a welding structure by a 1st embodiment. It is a front view which shows the arm in FIG. 1 alone. It is a disassembled perspective view shown in the state which decomposed | disassembled the arm and the reinforcement board. It is a front view which expands and shows the square cylinder, a reinforcement board, a fillet weld part, a deep penetration weld part, etc. in FIG. It is sectional drawing which looked at the web, the reinforcement board, the fillet weld part, and the deep penetration weld part from the arrow VV direction in FIG. It is a front view which shows the boom as a welding structure by 2nd Embodiment alone. It is the top view which expanded the square cylinder, the base end side boss | hub, a fillet weld part, and a deep penetration weld part from the arrow VII-VII direction in FIG. It is sectional drawing which looked at the square cylinder body, the base end side boss | hub, the fillet weld part, and the deep penetration weld part from the arrow VIII-VIII direction in FIG. It is a front view which expands and shows the square cylinder body in FIG. 6, a base end side boss | hub, a reinforcement board, a fillet weld part, and a deep penetration weld part. It is sectional drawing which looked at the square cylinder body, the reinforcement board, the fillet weld part, and the deep penetration weld part from the arrow XX direction in FIG. It is a front view which expands and shows the square cylinder body, arm attachment bracket, fillet weld part, and deep penetration weld part in FIG. It is sectional drawing which looked at the square cylinder, the arm attachment bracket, the fillet weld part, and the deep penetration weld part from the arrow XII-XII direction in FIG. It is a front view which shows the bucket as a welding structure by 3rd Embodiment alone. It is the left view which looked at the bucket from the arrow XIV-XIV direction in FIG. It is the same front view as FIG. 4 which shows the modification which crossed each deep penetration weld part orthogonally with respect to the fillet weld part formed between the web of the arm and the reinforcement board. It is a top view similar to FIG. 7 which shows the modification which made each deep penetration weld part incline and cross | intersect with the fillet weld part formed between the square cylinder body of a boom, and the base end side boss | hub.

Explanation of symbols

1 Hydraulic excavator 4 Working device 11 Arm (welded structure)
12,22 Square cylinder (one side member)
12A Left web 12B Right web 12C Upper flange 12D Lower flange 13 Boom boss 16, 26 Reinforcement plate (other side member)
17, 24, 27, 30, 51, 54 Fillet welded portion 18, 25, 28, 31, 52, 55, 61, 62 Deep penetration welded portion 21 Boom (welded structure)
23 Proximal boss (other side member)
29 Arm mounting bracket (other side member)
41 Bucket (welded structure)
42 Bottom plate (one side member)
44 Left side plate (one side member)
45 Right side plate (one side member)
50 Bottom plate reinforcement plate (other side member)
53 Side plate reinforcement plate (other side member)

Claims (3)

In the welded structure formed by joining the one side member and the other side member by fillet welding, including the one side member and the other side member joined to the one side member,
A configuration in which a plurality of deep penetration welds are provided at the position of the fillet welds so as to be melted in the plate thickness direction with respect to the one side member and the other side member in a state intersecting with the fillet welds. A welded structure characterized by that.   2. The welded structure according to claim 1, wherein each of the deep penetration welds is provided in a direction orthogonal to a welding direction of the fillet weld. The one side member is a rectangular tube body of a construction machine arm provided with a boom boss which is formed by being surrounded by left and right webs and upper and lower flanges and is pivotally attached to a boom of the construction machine. And
The other side member is a reinforcing plate fixed to the web of the rectangular tube body in order to reinforce the periphery of the boom boss,
Joining the web of the rectangular tube and the reinforcing plate by fillet welding,
2. The welded structure according to claim 1, wherein each deep penetration welded portion intersects the fillet welded portion and extends from the boom boss along a direction of main stress acting on the rectangular tube body. .

Images