JP2010221235A - Attachment of working machine, and welding method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute the fillet welding having sufficient strength without executing any grooving when manufacturing an attachment of a working machine. <P>SOLUTION: At least a part of corner parts 12 of butted portions 11 to a pair of flat plates 4, 5 in a pair of longitudinal plates 2, 3 are folded inwardly at an acute angle to outer surfaces of the longitudinal plates 2, 3 while keeping a right angle without any grooving, the folded corner parts 12 of the butted portions 11 are abutted on the flat plates 4, 5, and an outer corner part 13 formed between the butted portions 11 and a surface on the butted portion 11 side of the flat plates 4, 5 is welded so as to form a penetration bead 16 on the inner corner part 14. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an attachment for a work machine and a welding method thereof, and more particularly to improvement of fillet welding.

  Conventionally, as shown in FIG. 6, in a box-shaped structure such as an arm of a hydraulic excavator, a pair of vertical plates 202 are brought into contact with a pair of flat plates 205 to be assembled into a box shape. A welding method in which a right-angled outer corner portion 213 formed between the side surface and the side surface of the vertical plate 202 is welded on one side is known. In this welding method, there is a region that cannot be welded from the inside because it is assembled into a box shape, and in this region, the fillet weld 215 on the outer corner portion 213 side where welding is performed is sufficiently welded, but the inner corner portion In many cases, the penetration of 214 is insufficient, and when a load is applied to the welded portion, there is a problem that a crack is generated from an unwelded portion of the inner corner portion 214.

  Therefore, for example, in Patent Document 1, as shown in an example in FIG. 7, in the welding method in which the first base material 302 and the second base material 305 are butt-welded, the end portion of the first base material 302 is previously provided. The root face 302a and the one-side groove face 302b are formed on the surface 311. The root face 302a is brought into contact with the flat surface of the second base material 305, so that the first base material 302 and the second base material 305 are in contact with each other. There is a method in which the welding wire is exposed to the groove weld portion formed by the above-described method, and the contact portion between the first base material 302 and the second base material 305 is melted by an arc of the welding wire.

JP 2002-239723 A

  However, in the welding method as described in Patent Document 1, the groove 302b must be provided in a wide range of the first base material 302 (vertical plate) by machining or gas cutting, which is very time consuming and costly. There was a problem of being up.

  This invention is made | formed in view of this point, and the place made into the objective is to perform fillet welding with sufficient intensity | strength, without performing groove processing.

  In order to achieve the above object, in the present invention, the butted portion of the vertical plate is bent inward.

Specifically, the first invention is directed to an attachment for a work machine having a box-shaped structure in which a pair of vertical plates are butted perpendicularly between a pair of flat plates and welded to fillet,
The work machine attachment is
At least a part of the butted portion of the pair of vertical plates with respect to the pair of flat plates is bent at an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove,
In the state where the corner of the abutting portion maintaining the right angle is in contact with the flat plate, the outer corner formed between the corner and the surface of the flat plate on the abutting portion side is welded from the outside. The back bead is formed at the inner corner of the inner side.

  According to the above configuration, fillet welding can be performed on the outer corner portion without providing a groove in at least a part of the pair of vertical plates, and the corner portion of the butt portion is a surface on the butt portion side of the flat plate. Since the inner corners are formed not only on the outer side but also on the inner side, as in the case where grooves are provided on the inner side, the melt can easily flow into the inner corners and the backside bead is easily formed. Is formed. For this reason, the attachment of the working machine which has a box-shaped structure with high intensity | strength is easily obtained.

In the second invention, the attachment of a work machine having a box-shaped structure in which the flat plate is abutted against the ends of a pair of vertical plates of a member having a U-shaped cross section and is fillet welded,
The work machine attachment is
At least a part of the abutting portion with respect to the flat plate in the pair of vertical plates is bent at an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove,
The outer corner formed between the corner and the surface of the flat plate on the side of the butting portion is welded from the outside with the corners of the butting portion maintaining the right angle being in contact with the flat plate. The back bead is formed in the inner corner of the inner side.

  According to the above configuration, even when a flat plate is abutted against a U-shaped member like a small work machine, a fillet is formed at the outer corner without providing a groove in at least a part of the pair of vertical plates. Welding is possible, and the corners of the abutting part are in contact with the surface of each flat plate on the abutting part side. Corners are formed, and the back bead is easily formed because the melt easily flows into the inner corners. For this reason, the attachment of the working machine which has a box-shaped structure with high intensity | strength is easily obtained.

In the third invention, in the first or second invention,
All of the abutting portions are bent by an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing the groove.

  According to said structure, since welding is performed without providing a groove | channel in all the butt | matching parts, a manufacturing cost is cheap and a high intensity | strength attachment is obtained.

In a fourth invention, in any one of the first to third inventions,
Each end surface of the flat plate is arranged in the same plane as the outer surface of each vertical plate, and a corner portion welded to the fillet is formed at a substantially right angle.

  According to the above configuration, since it is possible to obtain the welding strength without forming a groove, it is not necessary to shift the vertical plate inward from the end surface of the flat plate to butt it into the T shape, so that the end surface of the flat plate and the vertical plate The outer surface can be arranged on the same plane, and the section modulus is larger than that of an attachment having a box-shaped structure with a T-shaped butt having the same width, and the strength of the attachment is improved. Conversely, when the end face of the flat plate is aligned with the outer surface of the conventional vertical plate, the weight is reduced by the amount that the flat plate is deleted while maintaining the same section modulus as that of the conventional attachment. In addition, since the corner is formed at a substantially right angle, it looks good, and the flat plate does not protrude from the vertical plate, so that when the attachment enters the soil during excavation work such as earth and sand, the sediment accumulates on the attachment. There is no.

In a fifth invention, a pair of vertical plates are butted vertically between a pair of flat plates and welded to fillet, and a welding method for manufacturing an attachment of a work machine is targeted.
In the above welding method,
Folding at least an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing the groove at least a part of the corners of the butted portion of the pair of vertical plates with respect to the pair of flat plates,
A corner portion of each of the bent butted portions is brought into contact with the flat plate to form an outer corner portion and an inner corner portion;
The outer corner portion is welded so that a back bead is formed at the inner corner portion.

  According to the above configuration, fillet welding can be performed on the outer corner portion without providing a groove in at least a part of the pair of vertical plates, and the corner portion of the butt portion is a surface on the butt portion side of the flat plate. Since the inner corners are formed not only on the outer side but also on the inner side, as in the case where grooves are provided on the inner side, the melt can easily flow into the inner corners and the backside bead is easily formed. Is formed. For this reason, the attachment of the working machine which has a box-shaped structure with high intensity | strength is easily obtained.

The sixth invention is directed to a welding method for manufacturing an attachment of a work machine that butt welds a flat plate to end portions of a pair of vertical plates of a member having a U-shaped cross-section,
In the above welding method,
Bending at least some corners of the abutting portion of the pair of vertical plates to the flat plate with an acute angle inside with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove,
The outer corner and the inner corner are formed by bringing the corners of the butted portion maintaining the right angle into contact with the flat plate,
The outer corner portion is welded so that a back bead is formed at the inner corner portion.

  According to the above configuration, even when a flat plate is abutted against a U-shaped member like a small work machine, a fillet is formed at the outer corner without providing a groove in at least a part of the pair of vertical plates. Welding is possible, and the corner of the butting part is in contact with the surface of the flat plate against the butting part. A back bead is easily formed because the melt is easy to flow into the inner corner. For this reason, the attachment of the working machine which has a box-shaped structure with high intensity | strength is easily obtained.

In the seventh invention, in the fifth or sixth invention,
It is set as the structure which bend | folds only an acute angle inside with respect to the outer surface of this vertical board, maintaining a right angle, without processing a groove | channel in all said each abutting part.

  According to said structure, since a groove | channel is not provided in all of each butt | matching parts, the attachment of the working machine which has a box-shaped structure which is further cheap and high intensity | strength is obtained.

In an eighth invention, in any one of the fifth to seventh inventions,
The corners of the bent butted portions are brought into contact with the flat plate so that the end surface of the flat plate and the outer surface of each vertical plate are in the same plane, and the corner portions are fillet welded at substantially right angles.

  According to the above configuration, since it is possible to obtain the welding strength without forming a groove, it is not necessary to shift the vertical plate inward from the end surface of the flat plate to butt it into the T shape, so that the end surface of the flat plate and the vertical plate The outer surface can be arranged on the same plane, and the section modulus is larger than that of an attachment having a box-shaped structure with a T-shaped butt having the same width, and the strength of the attachment is improved. Conversely, when the end face of the flat plate is aligned with the outer surface of the conventional vertical plate, the weight is reduced by the amount that the flat plate is deleted while maintaining the same section modulus as that of the conventional attachment. In addition, since the corner is formed at a substantially right angle, it looks good, and the flat plate does not protrude from the vertical plate, so that when the attachment enters the soil during excavation work such as earth and sand, the sediment accumulates on the attachment. There is no.

  As described above, according to the present invention, at least a part of the corners of the butted portion of the vertical plate has only an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing the groove. The fillet weld with sufficient strength is performed without performing groove processing by bending and butting it against a flat plate and performing fillet weld so that a back bead is formed at the inner corner. Can do.

  In addition, even if the outer surface of the vertical plate is arranged on the same plane as the end surface of the flat plate, sufficient weld strength can be obtained by fillet welding from one side, so a box structure with a high section modulus by increasing the width between the vertical plates Can be obtained. Moreover, weight reduction can also be achieved compared with the box-shaped structure of the conventional structure which has an equivalent section modulus. Furthermore, since there are no protrusions at the corners, it is difficult for dirt and the like to accumulate at the corners, and the mud dropping performance in excavation work of earth and sand can be significantly improved. Thus, according to the present invention, an attachment with high merchantability is obtained.

It is the II sectional view taken on the line of FIG. It is a side view of the arm concerning the embodiment of the present invention. It is sectional drawing which expands and shows the fillet weld part concerning embodiment of this invention. FIG. 6 is a view corresponding to FIG. 1 according to another embodiment of the present invention. It is the FIG. 1 equivalent view concerning other embodiment using the U-shaped member of this invention. FIG. 4 is a view corresponding to FIG. 3 for one-side fillet welding without applying conventional groove processing. FIG. 4 is a view corresponding to FIG. 3 for one-side fillet welding with conventional groove processing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 shows an arm 1 as a box-shaped structure according to an embodiment of the present invention, and this arm 1 is connected to an attachment distal end side of a hydraulic excavator (not shown) as a work machine. The arm 1 includes a pair of side plates (vertical plates 2 and 3) and a pair of flat plates 4 and 5 welded to the vertical plates 2 and 3. The left and right vertical plates 2 and 3 may be composed of a single sheet or a plurality of sheets. Moreover, in this embodiment, although the upper and lower flat plates 4 and 5 are comprised by multiple sheets, you may comprise by one sheet.

  The arm 1 includes first to third connection pin insertion holes 6, 7, and 8 for inserting connection pins for connecting other attachments on the front and rear sides. On the base end side of the arm 1, cylinder connecting portions 9 and 10 for connecting a hydraulic cylinder (not shown) connected to each attachment are formed so as to protrude from the flat plates 4 and 5. .

  As a feature of the present invention, as shown in enlarged views in FIGS. 1 and 3, the corner portion 12 of the abutting portion 11 with respect to the upper and lower flat plates 4 and 5 in the left and right vertical plates 2 and 3 processes a groove. The straight plate is bent at an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle, and is abutted against the surface of the flat plate 5 on the abutting portion 11 side. Between the outer surface of the butting portion 11 and the surface of the flat plates 4 and 5 on the butting portion 11 side, an acute outer corner portion 13 is formed. Similarly, an inner corner portion 14 having an angle smaller than that of the outer corner portion 13 is formed between the end surface of the butting portion 11 and the surface of the flat plates 4 and 5 on the abutting portion 11 side. A fillet weld 15 is continuously formed on the outer corner portion 13, and a back bead 16 is continuously formed on the inner corner portion 14.

  The end surfaces (left and right side surfaces) of the upper and lower flat plates 4 and 5 and the outer surfaces (left and right side surfaces) of the left and right vertical plates 2 and 3 are arranged on the same plane. Therefore, each corner portion 17 of the arm 1 is formed at a substantially right angle so that the flat plate 5 does not protrude from side to side.

-Welding method-
Next, a method for welding the corner portion 17 of the arm 1 of this embodiment will be described.

  First, the vertical plates 2 and 3 cut into a predetermined shape are prepared. The upper and lower ends of the vertical plates 2, 3, that is, the corners 12 of the abutting portion 11 with respect to the flat plates 4, 5 are kept at a right angle when the vertical plates 2, 3 are cut without machining the groove. For this reason, the labor for processing the groove can be saved, and the cost can be greatly reduced.

  Next, the corner portion 12 kept at a right angle of the abutting portion 11 is bent inward by an acute angle by a press machine or the like. Although press work is added in comparison with the prior art, machining is easier and cost increase is less than groove processing.

  Next, the corners 12 of the butted portion 11 are bent into the upper and lower flat plates 4 and 5 so that the left and right end surfaces of the upper and lower flat plates 4 and 5 and the outer surfaces of the left and right vertical plates 2 and 3 are in the same plane. Make contact. Then, the vertical plates 2 and 3 and the flat plates 4 and 5 are assembled into a box shape while being temporarily welded.

  Next, a welding wire (not shown) is made to face the outer corner portion 13 formed between the outer surface of the butting portion 11 and the surface of the flat plates 4 and 5 on the butting portion 11 side, and the outer corner is formed by the arc of the welding wire. The corner 13 is melted. At this time, the melt flows also into the inner corner portion 14 to form the back bead 16. That is, even if no groove is provided, the outer corner portion 13 having an acute angle is formed outside the right corner portion 12 and the inner corner portion 14 having an acute angle is formed on the inner side by bending. When the corner portion 13 is welded, the melt also flows into the inner corner portion 14. For this reason, the inner corner portion 14 is also sufficiently melted, and even if a load is applied to the welded portion, no crack is generated from the inner corner portion 14.

  In this way, since the welding strength can be obtained without forming a groove, it is not necessary to shift the vertical plates 2 and 3 inward from the end surfaces of the flat plates 4 and 5 and to butt them into a T-shape. 5 and the outer surfaces of the vertical plates 2 and 3 can be arranged on the same plane, and the section modulus becomes larger and the strength is improved as compared with a box-shaped structure having a T-shaped butt having the same width. Specifically, as shown in FIG. 6, in conventional fillet welding, the width b from the end surface to the center of the flat plate 205 is larger than the width a from the outer surface to the center of the vertical plate 202 in order to secure a welding region. Needs to be increased (b> a). On the other hand, in this embodiment, as shown in FIG. 3, the end surface of the flat plate 5 and the outer surface of the vertical plate 2 are in the same plane. For this reason, since the vertical plate 2 can be expanded to the width a, the section modulus of the arm 1 is improved. Furthermore, since the corner portion 17 is formed at a substantially right angle that does not protrude from side to side, the appearance is good. In this way, it is possible to obtain an attachment that is low in manufacturing cost and high in strength.

  Therefore, fillet welding can be performed on the outer corner portion 13 without providing a groove in the pair of vertical plates 2 and 3, and the corner portion 12 of the butting portion 11 is the butting portion 11 of each flat plate 4 and 5. The inner corner 14 is formed not only on the outer side but also on the inner side, as in the case where a groove is provided on the corner 12, and the melt flows into the inner corner 14. The back bead 16 is easily formed easily. For this reason, fillet welding with sufficient strength can be performed without performing groove processing.

  In addition, since the welding strength can be obtained without forming a groove, it is not necessary to shift the vertical plates 2 and 3 inward from the end surfaces of the flat plates 4 and 5 so as to abut the T-shape. The end surfaces and the outer surfaces of the vertical plates 2 and 3 can be arranged in the same plane, and the sectional modulus is larger than that of an arm formed by T-shaped butting having the same width, and the strength can be remarkably improved.

  Conversely, when the end surface of the flat plate 205 is aligned with the outer surface of the conventional vertical plate 202 shown in FIG. 6, a part of the flat plate 205 can be deleted while maintaining the same section modulus as that of the conventional arm. This is advantageous because it can be realized.

  Moreover, since the corner portion 17 is formed at a substantially right angle, the appearance is good, and the flat plates 4 and 5 do not protrude from the vertical plates 2 and 3, so that the arm 1 is in the soil during excavation work such as earth and sand. When entering, earth and sand do not collect in the corner portion 17 of the arm 1. For this reason, the arm 1 is hard to get dirty.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above-described embodiment, the upper and lower vertical plates 2 and 3 are both bent. For example, as shown in FIG. 4, only the upper side is bent, and the lower side is a normal one-side fillet weld 115. It is good. However, in this case, there is a drawback that the lower flat plate 105 protrudes from the outer surfaces of the vertical plates 2 and 3.

  Further, in the above embodiment, the pair of vertical plates 2 and 3 are abutted substantially vertically between the pair of flat plates 4 and 5 and are fillet welded. However, like the arm 401 shown in FIG. The flat plate 405 may be abutted against the ends of the pair of vertical plates 402a and 402b of the shaped member 402, and fillet welding may be performed as in the above embodiment. In that case, the same effect as the above embodiment can be obtained. The U-shaped cross-section member 402 is often used in a small hydraulic excavator arm or the like, so that further weight reduction and strength improvement can be achieved. Only one of the pair of vertical plates 402a and 402b may be bent.

  In the above-described embodiment, an example of an arm of a hydraulic excavator has been shown as a box-shaped structure, but the present invention is not limited to this, and can be applied to attachments of various work machines. Moreover, it is not limited to a working machine, What is necessary is just a box-shaped structure made by welding.

  In the above embodiment, the fillet weld 15 and the back bead 16 are continuously formed. However, depending on the box-shaped structure, the fillet weld 15 and the back bead 16 may be welded at intervals. In this case as well, the back bead 16 is necessarily formed at a portion where the fillet weld 15 is present.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

DESCRIPTION OF SYMBOLS 1 Arm 2,3 Vertical plate 4,5 Flat plate 6,7,8 Connection pin insertion hole 9,10 Cylinder connection hole 11 Butt | matching part 12 Corner | angular part 13 Outer corner part 14 Inner corner part 15 Fillet weld 16 Back wave bead 402 U-shaped members 402a, 402b A pair of vertical plates

Claims (8)

In the attachment of a work machine having a box-shaped structure in which a pair of vertical plates are butted perpendicularly between a pair of flat plates and are fillet welded,
At least a part of the butted portion of the pair of vertical plates with respect to the pair of flat plates is bent at an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove,
In the state where the corner of the abutting portion maintaining the right angle is in contact with the flat plate, the outer corner formed between the corner and the surface of the flat plate on the abutting portion side is welded from the outside. An attachment for a work machine, wherein a back bead is formed at an inner corner of the inner side. In the attachment of the work machine having a box-shaped structure in which the flat plate is abutted against the ends of the pair of vertical plates of the U-shaped member in cross section and welded fillet,
At least a part of the abutting portion with respect to the flat plate in the pair of vertical plates is bent at an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove,
The outer corner formed between the corner and the surface of the flat plate on the side of the butting portion is welded from the outside with the corners of the butting portion maintaining the right angle being in contact with the flat plate. An attachment for a working machine, wherein a back bead is formed at an inner corner of the inner side. In the attachment of the working machine according to claim 1 or 2,
An attachment for a working machine, wherein all of the butted portions are bent inward by an acute angle with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove. In the attachment of the working machine as described in any one of Claims 1 thru | or 3,
Each of the end surfaces of the flat plate is disposed in the same plane as the outer surface of each of the vertical plates, and a fillet welded corner is formed at a substantially right angle. In a welding method for manufacturing an attachment of a work machine that butt welds a pair of vertical plates substantially vertically between a pair of flat plates, and fillet welds,
Folding at least an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing the groove at least a part of the corners of the butted portion of the pair of vertical plates with respect to the pair of flat plates,
A corner portion of each of the bent butted portions is brought into contact with the flat plate to form an outer corner portion and an inner corner portion;
The welding method, wherein the outer corner portion is welded so that a back bead is formed at the inner corner portion. In a welding method for manufacturing an attachment of a work machine that butt welds a flat plate to end portions of a pair of vertical plates of a U-shaped member in a cross section,
Bending at least some corners of the abutting portion of the pair of vertical plates to the flat plate with an acute angle inside with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove,
The outer corners and inner corners are formed by bringing the corners of the butted portion maintaining the right angle into contact with the flat plate,
A welding method comprising welding the outer corner portion so that a back bead is formed at the inner corner portion. The welding method according to claim 5 or 6,
A welding method characterized by bending at an acute angle inward with respect to the outer surface of the vertical plate while maintaining a right angle without processing a groove in all the butted portions. The welding method according to any one of claims 5 to 7,
The end of the flat plate and the outer surface of each of the vertical plates are flush with each other so that the corners of the folded butted portions are brought into contact with the flat plate and the corner portions are fillet welded at substantially right angles. A welding method characterized.

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