JP5983666B2 - Welded structures and construction machinery - Google Patents

Description

The present invention relates to a welded structure and related technology.

  In construction machines such as hydraulic excavators, an attachment constituted by a boom and an arm is connected to the machine body. And the boss | hub used for a connection with another member is welded inside a boom or an arm. For example, in the hydraulic excavator described in Patent Document 1, the boss member (11) is welded to the arm (3).

JP-A-9-125441

  By the way, in the boss welded to the arm of the construction machine, as shown in FIG. 9 and FIG. 10, a cylindrical portion 71 extending in the axial direction DR and a flange portion protruding from both ends of the cylindrical portion 71. Some of them are configured to include 73a and 73b. As shown in FIGS. 9 and 10, the flange portions 73 a and 73 b include backing portions 75 a and 75 b that are in contact with the back surface of the side plate of the arm at the edges (outer edges).

  However, in the boss BS2 shown in FIGS. 9 and 10, since the backing portions 75a and 75b do not have a sufficient width, there is a possibility that the following welding failure will occur.

  FIG. 11 shows a state in which the boss BS2 is welded to the arm of the construction machine. As shown in FIG. 11, in the welding of the boss BS2, the boss BS2 and the left side plate 43 are first welded to form a weld metal on the welding line LN1.

  Thereafter, gouging is performed on the broken line area AR shown in the enlarged portion of FIG. Gouging means that the portion of the weld metal formed by the immediately preceding welding operation is scraped off (curled). Here, by performing gouging on the broken line area AR, a portion of the weld metal formed on the welding line LN1 that hinders the welding between the boss BS2 and the lower plate 42 to be performed next is cut. For convenience of explanation, the weld metal is not shown in the enlarged portion of FIG. 11, but actually there is a weld metal.

  When the gouging for the broken line area AR is completed, the boss BS2 and the lower plate 42 are now welded, and a weld metal is formed on the welding line LN2.

  12 is a cross-sectional view at the position XII-XII in FIG. In particular, FIG. 12A shows a state where the weld metal AD is formed in a state where the flange 73 and the left side plate 43 are normally assembled. FIG. 12B shows a state where the weld metal AD is formed in a state where an assembly error has occurred between the flange 73 and the left side plate 43.

  As shown in FIG. 12B, when an assembly error occurs between the flange 73 and the left side plate 43, a hole is opened near the point PT, which may cause poor welding.

  13 is a cross-sectional view at the position XIII-XIII in FIG. As is clear when FIG. 12A is compared with FIG. 13, the edge of the left side plate 43 is gradually tapered. Therefore, when gouging is performed on the area AR in FIG. 11, the edge of the left side plate 43 (see FIG. 13) penetrates, which may cause poor welding.

  As described above, the boss BS2 of the comparative example shown in FIGS. 9 and 10 has a problem that poor welding may occur due to assembly errors and gouging. Note that such a problem of poor welding is not limited to a welded structure such as an arm or a boss, and the same problem may occur in other welded structures.

  Then, an object of this invention is to provide the welding structure which can suppress generation | occurrence | production of a welding defect, and the technique relevant to it.

In order to achieve the above object, the present invention provides a welded structure including a first plate, a second plate, and a third plate, wherein an edge of the first plate and an edge of the second plate are provided. The edge of the second plate has a backing portion that extends along the abutting portion with the edge of the first plate and abuts against the back surface of the first plate; The second plate is welded to the first plate in a state where the backing portion is in contact with the back surface of the first plate, and the first plate and the second plate are welded to each other. The edge part which comprises a joining board and intersects with the welding line of the 1st board and the 2nd board among the edge parts of the joining board is butted against one side of the 3rd board, and is welded, At the end of the backing portion in contact with the third plate, protrusions provided we are projecting direction from the second plate to the first plate, the projecting portion Width provides a welded structure, wherein the width is wider than the other portions where the projecting portions are not provided out of the backing portion.

  Further, it is preferable that an angle formed between a welding line for welding the first plate and the second plate and a welding line for welding the joining plate and the third plate has a predetermined angle other than a right angle.

  Moreover, the said welded structure is a can manufacturing structure provided with a boss | hub inside, the said 1st board is a side plate which comprises the said can manufacturing structure, and the said 2nd board is a flange part of the said boss | hub. In addition, it is preferable that the third plate is one of an upper plate and a lower plate constituting the can making structure.

Moreover, this invention is a construction machine, Comprising: A machine main body and the attachment connected to the said machine main body, The said attachment is a welding structure containing a 1st board, a 2nd board, and a 3rd board. The welded structure has an edge of the first plate and an edge of the second plate abutted, and the edge of the second plate is abutted with the edge of the first plate A backing portion extending along the portion and abutted against the back surface of the first plate; and the second plate is configured such that the backing portion is in contact with the back surface of the first plate. Welded to one plate, and the first plate and the second plate are welded together to form a joining plate, and the first plate and the second plate among the edges of the joining plate, The edge that intersects the welding line is butted against one surface of the third plate and welded, and contacts the third plate At the end of the abutting portion, the protrusion protruding is provided et be the second plate in a direction toward the first plate, the width of the protrusion, has the projecting portion is provided out of said backing portion Further provided is a construction machine characterized in that it is wider than other parts that are not.

  According to the welded structure of claim 1, since there is a protruding portion that protrudes in the direction from the second plate toward the first plate at the end of the backing portion that contacts the third plate, there is an assembly error or gouging. Can be prevented from penetrating through the first plate, and the occurrence of poor welding can be suppressed.

  According to the welded structure of claim 2, the angle formed between the welding line for welding the first plate and the second plate and the welding line for welding the joining plate and the third plate forms a predetermined angle other than a right angle. Therefore, it is possible to reduce the stress applied to each member.

  According to the welded structure of claim 3, since there is a protruding portion that protrudes in the direction from the flange portion of the boss toward the side plate at the end of the backing portion that contacts the lower plate or the upper plate, It is possible to prevent the side plate from penetrating due to gouging and to suppress the occurrence of poor welding.

  According to the construction machine of the fourth aspect, it is possible to prevent the first plate from penetrating due to an assembly error or gouging, and to suppress the occurrence of poor welding.

1 is a side view showing a hydraulic excavator according to an embodiment of the present invention. The side view of an arm. A side view of the boss. IV arrow line view of FIG. The figure which expanded the welding location of the side plate of an arm, and the flange part of a boss | hub. Sectional drawing of the VI-VI position of FIG. The side view which shows the boss | hub which concerns on a modification. VIII arrow directional view of FIG. The side view which shows the boss | hub which concerns on a comparative example. X arrow line view of FIG. The figure which expanded the welding location which concerns on a comparative example. Sectional drawing of the XII-XII position of FIG. Sectional drawing of the XIII-XIII position of FIG.

<1. Embodiment>
A construction machine and a welded structure according to an embodiment of the present invention will be described with reference to FIGS. Hereinafter, a hydraulic excavator 1 will be described as an example of a construction machine, and an arm (also referred to as an arm can) 24 will be described as an example of a welded structure.

  As shown in FIG. 1, the hydraulic excavator 1 includes a crawler type lower traveling body 2 and an upper swing body 3.

  The upper swing body 3 is mounted on the lower travel body 2 and can swing around the vertical axis with respect to the lower travel body 2. A work attachment 4 is mounted on the upper swing body 3. The work attachment 4 includes a boom 14 that can be raised and lowered, an arm 24 that is rotatably attached to the tip of the boom 14, and a bucket 34 that is attached to the tip of the arm 24.

  Hereinafter, the arm 24 of the present embodiment will be specifically described with reference to FIGS. 2 to 6. In FIG. 2, for the sake of convenience, the left-right direction of the drawing is described as the front-rear direction of the arm 24.

  As shown in FIG. 2, the arm 24 includes an upper plate 41, a lower plate 42, a left side plate 43, and a right side plate 44. The arm 24 includes a boss BS1 at the base end (also referred to as an arm foot). The boss BS1 is welded to the left plate 43 and the right plate 44 and to the lower plate 42. The arm 24 is pivotally attached to the boom 14 (FIG. 1) by inserting a connecting pin through the boss BS1.

  As shown in FIGS. 3 and 4, the boss BS <b> 1 includes a cylindrical portion 61 that extends in the axial direction DR, and flange portions 63 a and 63 b that protrude from both ends of the cylindrical portion 61. The edge portion (end portion) 64a of the flange portion 63a is abutted against the edge portion 43e (see FIG. 5) of the left side plate 43 when welding the left side plate 43 and the boss BS1. Similarly, the edge portion (end portion) 64b of the flange portion 63b is abutted against the edge portion (not shown) of the right side plate 44 when welding the right side plate 44 and the boss BS1.

  Further, a backing portion 65a is formed on the edge portion 64a of the flange portion 63a, and a backing portion 65b is formed on the edge portion 64b of the flange portion 63b.

  As shown in FIG. 5, the backing portion 65 a extends along the abutting portion with the left side plate 43. The backing portion 65 a abuts against the back surface of the left side plate 43 (inside the arm 24) in a state where the flange portion 63 a is abutted against the left side plate 43.

  Although not shown, the backing portion 65b also extends along the abutting portion with the right side plate 44, and the back surface (the arm 24 of the arm 24) of the right side plate 44 in a state where the flange portion 63b is abutted against the right side plate 44. Abutting on the inside).

  As shown in FIGS. 3 to 5, the backing portion 65 a includes a protruding portion 67 a at an end portion in contact with the lower plate 42. The protruding portion 67a protrudes from the flange portion 63a toward the left side plate 43. Similarly, the backing portion 65b also includes a protruding portion 67b at an end portion in contact with the lower plate. The protruding portion 67b protrudes from the flange portion 63b toward the right side plate 44. That is, in the protrusions 67a and 67b, the width of the backing portion is wider than the other portions.

  In the present embodiment, as shown in FIG. 5, first, the left side plate 43 and the flange portion 63a of the boss BS1 are welded along the welding line LN1, thereby forming a weld metal on the welding line LN1. In other words, the left side plate 43 and the flange portion 63a of the boss BS1 constitute a single joining plate by being welded to each other.

  Then, of the weld metal formed on the welding line LN1, gouging is performed on a portion that hinders the welding operation between the lower plate 42 and the flange portion 63a of the boss BS1 to be performed next.

  Thereafter, an edge (a portion corresponding to the welding line LN2) of the joining plate (the left side plate 43 and the flange portion 63a welded to each other) intersecting the welding line LN1 is abutted against the surface of the lower plate. Then, the lower plate 42 and the joint plate are welded along the welding line LN2, and a weld metal is formed on the welding line LN2.

  For convenience of explanation, the weld metal is not shown in the enlarged portion of FIG. 5, but it is assumed that the weld metal is actually formed on the welding lines LN1, LN2. Although not shown, the right side plate 44 and the flange portion 63b are also welded by the same configuration as the left side plate 43 and the flange portion 63a.

  Moreover, in this embodiment, as shown in FIG. 5, it is comprised so that the angle which the welding lines LN1 and LN2 make may have predetermined angles other than a right angle. Therefore, it is possible to reduce the stress applied to each member as compared with the case where the angle formed by the welding lines LN1 and LN2 is a right angle.

  6 is a cross-sectional view taken along the line VI-VI in FIG. As is clear from a comparison between FIG. 6 and FIG. 12A, in the present embodiment, since the protruding portion 67a (FIGS. 4 and 5) is provided in the backing portion 65a, the back surface of the left side plate 43 is provided. The area of the backing portion 65a to be abutted is larger than that of the comparative example shown in FIG.

  Therefore, even if a slight assembly error occurs between the left side plate 43 and the flange portion 63a of the boss BS1, there is a low possibility that a hole as shown in FIG. Further, even if the left side plate 43 is largely shaved by gouging, the presence of the protruding portion 67a can prevent the left side plate 43 from penetrating.

  Thus, in the arm 24 according to the present embodiment, it is possible to suppress poor welding of the arm 24 due to the presence of the protruding portion 67a provided in the backing portion 65a.

  In particular, in the present embodiment, since the protruding portion 67a is provided at the end of the backing portion 65a in contact with the lower plate 42, the weight can be reduced as compared with the case where the width of the backing portion 65a is increased as a whole. Figured.

<2. Modification>
The construction machine and the welded structure according to the present invention are not limited to the above-described embodiments, and various modifications and improvements can be made within the scope described in the claims.

  For example, in the above embodiment, the idea of the present invention is applied to the arm 24 having the boss BS1 (FIGS. 3 and 4) inside, but the boss BS3 (FIGS. 7 and 8) is not limited to this. You may apply the thought of this invention to the boom which has.

  Specifically, as shown in FIGS. 7 and 8, a backing portion 85 is provided at the edge of the flange portion 83 that faces the edge of the side plate of the boom, and the lower plate or the upper plate of the boom, or both What is necessary is just to make it provide the protrusion part 87 in the edge part of the backing part 85 which touches.

  In such a modification, it is possible to suppress the welding failure of the boom due to the presence of the protruding portion 87 provided on the backing portion 85.

  Moreover, although the said embodiment and the modification illustrated the case where the thought of this invention was applied to the arm and boom which have a boss | hub, it is not limited to this.

  For example, the idea of the present invention is applied to a welded structure produced by welding a joining plate in which an edge of one plate and an edge of another plate are abutted and welded to one surface of another plate. You may apply.

  As described above, the welded structure according to the present invention is suitable for, for example, an arm or boom of a construction machine including a boss therein.

1 hydraulic excavator, 2 lower traveling body, 3 upper turning body, 4 work attachment,
14 Boom, 24 Arm, 34 Bucket, 41 Upper plate, 42 Lower plate,
43 left side plate, 43 left side plate, 44 right side plate, 61 cylindrical part,
63a, 63b flange part, 63b flange part, 65a, 65b backing part,
67a, 67b protrusion, 71 cylindrical portion, 73 flange,
73a, 73b flange part, 75a, 75b backing part,
AR broken line area, BS1 to BS3 boss, DR axial direction, LN1, LN2 welding line

Claims (4)

A welded structure comprising a first plate, a second plate, and a third plate,
The edge of the first plate and the edge of the second plate are abutted,
The edge of the second plate has a backing portion that extends along the abutting portion with the edge of the first plate and abuts against the back surface of the first plate;
The second plate is welded to the first plate with the backing portion in contact with the back surface of the first plate,
The first plate and the second plate constitute a joining plate by being welded to each other,
Of the edges of the joining plate, the edge that intersects the welding line of the first plate and the second plate is butted against one surface of the third plate, and is welded.
Wherein the third end portion of the backing portion in contact with the plate, protrusions provided we are projecting direction from the second plate to said first plate,
The width of the said protrusion part is wider than the width | variety of the other part in which the said protrusion part is not provided among the said backing parts, The welding structure characterized by the above-mentioned. The welded structure according to claim 1,
A welding structure characterized in that an angle formed between a welding line for welding the first plate and the second plate and a welding line for welding the joining plate and the third plate has a predetermined angle other than a right angle. . In the welded structure according to claim 1 or 2,
The welded structure is a can-making structure having a boss inside,
The first plate is a side plate constituting the can making structure,
The second plate is a flange portion of the boss;
The welded structure, wherein the third plate is one of an upper plate and a lower plate constituting the can making structure. A construction machine,
The machine body,
An attachment connected to the machine body;
With
The attachment has a welded structure including a first plate, a second plate, and a third plate,
The welded structure is
The edge of the first plate and the edge of the second plate are abutted,
The edge of the second plate has a backing portion that extends along the abutting portion with the edge of the first plate and abuts against the back surface of the first plate;
The second plate is welded to the first plate with the backing portion in contact with the back surface of the first plate,
The first plate and the second plate constitute a joining plate by being welded to each other,
Of the edges of the joining plate, the edge that intersects the welding line of the first plate and the second plate is butted against one surface of the third plate, and is welded.
The the third end portion of the backing portion in contact with the plate, protrusions provided we are projecting direction from the second plate to said first plate,
The construction machine characterized in that the width of the protruding portion is wider than the other portion of the backing portion where the protruding portion is not provided .

Images