JP5696101B2 - Drilling bucket - Google Patents

Description

  The present invention relates to an excavation bucket that is installed in a construction machine such as a hydraulic excavator and is preferably used for excavation work of earth and sand.

  In general, a hydraulic excavator as a representative example of a construction machine is a self-propelled lower traveling body, an upper revolving body that is swingably mounted on the lower traveling body, and can be raised and raised on the front side of the upper revolving body. And a working device provided. The excavator working device includes a boom, an arm, a digging bucket, and the like, and performs excavation work such as earth and sand by rotating the digging bucket on the tip side of the arm.

  This excavation bucket is usually a bucket base having a bottom plate formed in a concave curve between a lower front end and an upper front end and left and right side plates provided on the left and right sides of the bottom plate; The front bottom plate located at the lower front end of the bottom plate located between the right side plates, the left front side plate provided at the front end of the left side plate, the right front side plate provided at the front end of the right side plate, and the upper front end side of the bottom plate And a bracket that is rotatably connected to the tip of the arm via a connecting pin.

  By the way, a drilling bucket in which a bottom plate, left and right side plates, a front bottom plate, and left and right front plates are integrally formed by casting is known. Thus, by using the casting method, the shape of the excavation bucket can be freely designed, and an excavation bucket excellent in mud sweepability can be formed (Patent Document 1).

JP 2010-53590 A

  By the way, when casting a digging bucket, since the large sized casting equipment corresponding to a digging bucket is needed, there exists a problem that the manufacturing cost of a digging bucket will increase.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a drilling bucket that is excellent in mud scavenging properties and can reduce manufacturing costs.

  In order to solve the above-described problems, the present invention provides a bucket base having a bottom plate formed in a concave curve between a lower front end and an upper front end, and left and right side plates provided on both left and right sides of the bottom plate. A front bottom plate provided at a lower front end of the bottom plate located between the side plates of the bucket base, a left front plate provided at a front end of the left side plate of the bucket base, and the right side of the bucket base The excavation bucket is provided with a right front plate provided at a front end of the plate and a pair of brackets provided on the upper front end side of the bottom plate and rotatably connected to a work machine via a connection pin.

  The invention according to claim 1 is characterized in that the bucket base and the pair of brackets are integrally formed using a casting means to form a base-side unit, and the front bottom plate and the left and right fronts are formed. The side plate is formed individually using a cast or steel plate material, and the front bottom plate and the left and right front side plates are joined to the base body-side unit by welding means.

  According to a second aspect of the present invention, the front bottom plate and the left and right front side plates are joined to the substrate-side integrated body in a state of being subjected to a quenching process for increasing hardness.

  According to a third aspect of the present invention, there is provided a structure in which a groove is provided at the base-side joining end joined to the front bottom plate and the front side plates in the base-side integrated body formed by using casting means. .

  According to a fourth aspect of the present invention, in the case where the front bottom plate and / or the left and right front side plates are formed using a casting, the front bottom plate and / or the left and right front side plates are integrated with the base body side. The present invention has a configuration in which a groove is provided at the front bottom plate side joint end and / or the front plate side joint end joined to the object.

  According to a fifth aspect of the present invention, there is formed a front plate assembly in which the front bottom plate and the left and right front side plates are preliminarily assembled together, and the front plate assembly is welded to the base-side unit. It is that it was set as the structure joined by.

  According to the invention of claim 1, a bucket base having a bottom plate and left and right side plates and a pair of brackets provided on the upper front end side of the bottom plate are formed by casting as a base side integral, and this base side integral The excavation bucket can be manufactured by joining the front bottom plate and the left and right front side plates to the object by welding. Thereby, the shape of a bucket base | substrate can be freely formed by casting and the mud sweeping property of an excavation bucket can be improved. In addition, by casting a base-side unit consisting of a bucket base and a pair of brackets, the scale of the casting equipment can be reduced as compared with the case of casting the entire excavation bucket. As a result, it is possible to manufacture a drilling bucket with good mud sweepability while reducing manufacturing costs.

  According to the second aspect of the present invention, the front bottom plate and the left and right front plates are hardened in advance by joining the front bottom plate and the left and right front side plates before joining to the base body-side unit. , The right front plate can be joined to the base-side unitary body, and the durability of the excavation bucket can be improved. In addition, after the excavation bucket is manufactured by quenching the front bottom plate and the left and right front plates having a small outer shape, the front bottom plate and the left and right front plates of the excavation bucket are quenched. Compared with the case of applying, the waste of the quenching work can be eliminated and the workability can be improved.

  According to the invention of claim 3, when the base-side unitary object and the front bottom plate are joined by welding, a good weld bead is formed between the groove provided at the base-side joining end and the front bottom plate. It is possible to increase the bonding strength between the substrate-side integrated object and the front bottom plate. On the other hand, when joining the base-side unit and the left and right front plates by welding, it is possible to form a good weld bead between the groove provided at the base-side joint end and each front plate. In addition, it is possible to increase the bonding strength between the substrate-side integral and the left and right front plates.

  In this case, a groove can be formed at the base-side joining end of the base-side integral by a mold during casting. Thereby, it is not necessary to post-process the groove at the base-side joining end, and the manufacturing cost of the base-side integrated body including the groove can be reduced.

  According to the invention of claim 4, when the front bottom plate and / or the left and right front side plates are formed by casting, a groove is formed at the front bottom plate side joining end and / or the front side plate side joining end by a mold. I can keep it. As a result, when the front bottom plate and / or the left and right front plates formed by casting are joined to the base-side unit by welding, the opening formed at the base-side joint end of the base-side unit is formed. A V-shaped groove can be formed by the front and the front bottom plate and / or the front bottom plate side joint end and / or the front plate side joint end of the left and right front side plates. As a result, it is possible to further increase the bonding strength between the base-side integrated object and the front bottom plate and the bonding strength between the base-side integrated object and the left and right front side plates, thereby increasing the strength of the entire excavation bucket.

  According to the invention of claim 5, by assembling the front plate assembly with the front bottom plate and the left and right front side plates, and joining the front plate assembly to the base-side unit, the front bottom plate and the left and right side plates are joined. The workability at the time of assembling the excavation bucket can be improved as compared with the case where the front plate is individually joined to the base body-side unit.

It is a front view which shows the hydraulic shovel provided with the excavation bucket by the 1st Embodiment of this invention. It is a perspective view which shows the excavation bucket by 1st Embodiment alone. It is a disassembled perspective view in the state which decomposed | disassembled the base | substrate side integrated object, the front bottom board, the left front side board, and the right front side board. It is a perspective view which shows the state which joined the base plate and the front bottom board and the left and right front board. It is a perspective view which shows the state which attaches a digging nail | claw to a front bottom board and attaches a side cutter to the left and right front side board. It is an expanded sectional view seen from the arrow VI-VI direction in FIG. 4 which shows the junction part of a base | substrate side integrated object and a front bottom board. It is an expanded sectional view seen from the arrow VII-VII direction in FIG. 4 which shows the junction part of a base | substrate side integrated object and a left front side board. It is a perspective view which shows the excavation bucket by 2nd Embodiment alone. It is a disassembled perspective view in the state which decomposed | disassembled the base | substrate side integrated object, the front bottom board, the left front side board, and the right front side board. It is a perspective view which shows the state which joined the base plate and the front bottom board and the left and right front board. It is a perspective view which shows the state which attaches a side cutter to the left and right front plates. It is an expanded sectional view seen from the arrow XII-XII direction in FIG. 10 which shows the junction part of a base | substrate side integrated object and a front bottom board. It is an expanded sectional view seen from the arrow XIII-XIII direction in FIG. 10 which shows the junction part of a base | substrate side integrated object and a left front side board. It is a perspective view which shows the excavation bucket by 3rd Embodiment alone. It is a disassembled perspective view in the state which decomposed | disassembled the base | substrate side integrated object, the front bottom board, the left front side board, the right front side board, and the excavation claw. It is a perspective view which shows the state which joined the base plate and the front bottom board and the left and right front board. It is an expanded sectional view seen from the arrow XVII-XVII direction in FIG. 16 which shows the junction part of a base | substrate side integrated object and a front bottom board. It is an expanded sectional view seen from the arrow XVIII-XVIII direction in FIG. 16 which shows the junction part of a base | substrate side integrated object and a left front side board. It is a perspective view which shows the excavation bucket by 4th Embodiment alone. It is a disassembled perspective view in the state which decomposed | disassembled the base | substrate side integrated object, the front bottom board, the left front side board, and the right front side board. It is an expanded sectional view seen from the arrow XXI-XXI direction in FIG. 19 which shows the junction part of a base | substrate side integrated object and a front bottom board. It is the expanded sectional view seen from the arrow XXII-XXII direction in FIG. 19 which shows the junction part of a base | substrate side integrated object and a left front side board. It is a disassembled perspective view which shows the state which joins the front board assembly which assembled the front baseplate and the left and right front board by a modification to a base | substrate side integrated object.

  Hereinafter, an embodiment of the excavation bucket according to the present invention will be described in detail with reference to the accompanying drawings, taking an excavation bucket equipped in a hydraulic excavator as an example.

  First, FIG. 1 thru | or FIG. 7 has shown 1st Embodiment of the excavation bucket based on this invention.

  In the figure, reference numeral 1 denotes a hydraulic excavator as a typical example of a construction machine. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2 and an upper swing that is rotatably mounted on the lower traveling body 2. The body 3 is roughly configured. A working device 4 is provided on the front side of the swivel frame 3 </ b> A that serves as a base of the upper swing body 3 so as to be able to move up and down, and the work device 4 performs excavation work of earth and sand.

  Here, the working device 4 includes a swing post 5 attached to the front end side of the swing frame 3A so as to be swingable in the left and right directions, a boom 6 attached to the swing post 5 so as to be able to be raised and lowered, and the boom. 6, an arm 7 attached to the front end side of the arm 6 so as to be able to move up and down, an excavation bucket 11 described later attached to the front end side of the arm 7 so as to be rotatable using a connecting pin 8, and one end side pin-coupled to the arm 7 The other end side of the bucket link 10 connected to the excavation bucket 11 using the connection pin 9, the boom cylinder 6 </ b> A provided between the swing post 5 and the boom 6, and the boom 6 and the arm 7. The arm cylinder 7 </ b> A and the bucket cylinder 10 </ b> A provided between the arm 7 and the bucket link 10 are roughly configured. And the working device 4 performs the excavation work of earth and sand etc. by rotating the excavation bucket 11 on the front end side of the arm 7 while raising and lowering the boom 6 and the arm 7.

  Next, a specific configuration of the excavation bucket used in the first embodiment will be described.

  Reference numeral 11 denotes an excavation bucket that is pivotally attached to the distal end side of the arm 7 using a connecting pin 8. The excavation bucket 11 is rotated about the connecting pin 8 by expanding and contracting the bucket cylinder 10A, excavating the ground and the like, scooping up the soil, and discharging it to a desired soil discharge location.

  As shown in FIGS. 2 and 3, the excavation bucket 11 is roughly configured by a bucket base 13 described later, a pair of brackets 19 and 20, a front bottom plate 21, a left front side plate 22, and a right front side plate 23. . In this case, as shown in FIG. 3, the bucket base 13 and the pair of brackets 19 and 20 are integrally formed using a casting means, for example, and are configured as a base-side integrated body 12 made of cast iron or cast steel. ing.

  Reference numeral 13 denotes a bucket base serving as a base of the excavation bucket 11. The bucket base 13 is made of a cast product, and constitutes the base-side integrated body 12 together with brackets 19 and 20 described later. Here, the bucket base 13 includes a bottom plate 14, a left side plate 15, and a right side plate 16 which will be described later.

  Reference numeral 14 denotes a bottom plate that forms the bottom of the bucket base 13, and the bottom plate 14 includes a lower front end 14A, an upper front end 14B, and a concave curved curved surface 14C formed between the lower front end 14A and the upper front end 14B. Therefore, it is configured as a plate having a U-shaped cross-sectional shape as a whole. Then, an after-mentioned earth and sand accommodating portion 17 is formed on the inner surface 14D side of the bottom plate 14, and on the outer surface 14E side of the bottom plate 14, brackets 19 and 20 described later are provided in the vicinity of the upper front end 14B. Yes.

  Here, the lower front end 14A of the bottom plate 14 extends in the left and right directions, and a front bottom plate 21 described later is joined using welding means. For this reason, as shown in FIG. 6, the edge part of 14 A of lower front ends becomes the baseplate side junction end 14F as a base | substrate side junction end, and the baseplate side groove | channel 14G is formed in this baseplate side junction end 14F. The bottom plate side groove 14G is inclined from the edge of the bottom plate side joint end 14F toward the outer surface 14E of the bottom plate 14, and the groove angle θ1 of the bottom plate side groove 14G is set to 45 °, for example. In this case, the bottom plate side groove 14 </ b> G is not formed by post-processing such as cutting on the bottom plate side joint end 14 </ b> F of the bottom plate 14, but is formed at the time of casting the base body side integrated body 12.

  Reference numeral 15 denotes a left side plate provided on the left side of the bottom plate 14, and 16 denotes a right side plate provided on the right end side of the bottom plate 14. These left and right side plates 15 and 16 face each other in the left and right directions with the bottom plate 14 interposed therebetween, and extend between the lower front end 14A and the upper front end 14B of the bottom plate 14 in the upward and downward direction. And are integrally molded.

  Here, on the front end 15A of the left side plate 15, a left side plate side joint end 15B as a base end side joint end cut out in an inverted L shape from the vicinity of the upper front end 14B of the bottom plate 14 is upward and downward. It is extended. Since a left front side plate 22 to be described later is joined to the left side plate side joining end 15B using welding means, the left side plate side joining end 15B of the left side plate 15 has a left side plate side opening as shown in FIG. A tip 15C is formed. The left side plate side groove 15C is inclined from the edge of the left side plate side joint end 15B toward the outer surface 15D of the left side plate 15, and the left side plate side groove 15C has a groove angle θ2 set to, for example, 45 °. Has been.

  On the other hand, on the front end 16A of the right side plate 16, a right side plate side joint end 16B as a base end side joint end cut out in an inverted L shape from the vicinity of the upper front end 14B of the bottom plate 14 extends upward and downward. Is provided. Since a right front side plate 23 to be described later is joined to the right side plate side joining end 16B using welding means, the right side plate similar to the left side plate side joining end 15B is also attached to the right side plate side joining end 16B of the right side plate 16. A side groove (not shown) is formed.

  Thus, the bucket base 13 is constituted by the bottom plate 14, the left side plate 15 and the right side plate 16, and the space surrounded by the bottom plate 14 and the left and right side plates 15, 16 accommodates the earth and sand of the bucket base 13. It is part 17. An opening 18 of the bucket base 13 is formed by the lower front end 14A and the upper front end 14B of the bottom plate 14, the front end 15A of the left side plate 15, and the front end 16A of the right side plate 16.

  Next, 19 indicates a left bracket provided on the upper front end 14B side of the bottom plate 14, and 20 indicates a right bracket which is paired with the left bracket 19 and provided on the upper front end 14B side of the bottom plate 14. Here, the left and right brackets 19 and 20 are integrally formed with the bucket base 13 using a casting means, and the base-side integrated body 12 including the left and right brackets 19 and 20 and the bucket base 13 is cast. ing.

  The left and right brackets 19 and 20 are connected to the arm 7 of the working device 4 shown in FIG. For this reason, the left and right brackets 19 and 20 face each other at a constant interval in the left and right directions, and the pin insertion holes 19A and 20A through which the connection pin 8 shown in FIG. 1 is inserted and the connection pin 9 are inserted. Pin insertion holes 19B and 20B are respectively drilled.

  As described above, in the present embodiment, the bucket base 13 including the bottom plate 14 and the left and right side plates 15 and 16 and the pair of left and right brackets 19 and 20 are integrally formed using casting means. Thus, the substrate-side integrated object 12 is cast. In this case, the bucket base 13 includes a bottom plate 14 to which a later-described front bottom plate 21 is not joined, a left-side plate 15 to which a later-described left front side plate 22 is not joined, and a right-side plate 16 to which a later-described right front side plate 23 is not joined. It is comprised by.

  Thereby, the external shape of the base | substrate side integrated object 12 which consists of the bucket base | substrate 13 and the left and right brackets 19 and 20 can be restrained small. Therefore, for example, when forming the base-side integrated body 12 using a shell mold casting method, the casting equipment is compared with the case where the entire excavation bucket including the front bottom plate 21, the left and right front plates 22 and 23 is cast. The size can be reduced.

  Next, 21 denotes a front bottom plate (cutting edge) provided at the lower front end 14A of the bottom plate 14, and the front bottom plate 21 is formed in a rectangular flat plate shape extending in the left and right directions. The front bottom plate 21 is located between the left and right side plates 15 and 16 of the bucket base 13 and is joined to the bottom plate-side joining end 14F provided at the lower front end 14A of the bottom plate 14 using welding means.

  Here, the front bottom plate 21 is formed using, for example, a steel plate material, and the thickness dimension of the front bottom plate 21 is set to be larger than the thickness dimension of the lower front end 14 </ b> A of the bottom plate 14 constituting the bucket base 13. In addition, the hardness of the front bottom plate 21 is increased by performing a quenching process in advance before the front bottom plate 21 is welded to the bottom plate-side joining end 14F of the bottom plate 14. Accordingly, the front bottom plate 21 has sufficient rigidity against an impact received from the ground when the excavation bucket 11 is used to excavate the ground or the like.

  Reference numeral 22 denotes a left front side plate (left side edge) provided at the front end 15 </ b> A of the left side plate 15. The left front side plate 22 is formed in a substantially rectangular flat plate shape that extends upward and downward using, for example, a steel plate material, and three bolt insertion holes 22A for attaching a left side cutter 25 described later are provided on the lower end side thereof. It has been drilled. The left front side plate 22 is joined to the left side plate-side joining end 15B of the left side plate 15 and the upper surface of the front bottom plate 21 using welding means.

  Reference numeral 23 denotes a right front side plate (right side edge) provided at the front end 16 </ b> A of the right side plate 16. The right front side plate 23 is formed in a substantially rectangular flat plate shape extending upward and downward using, for example, a steel plate material, and three bolt insertion holes 23A for attaching a right side cutter 26 described later are provided on the lower end side thereof. It has been drilled. The right front side plate 23 is joined to the right side plate side joining end 16B of the right side plate 16 and the upper surface of the front bottom plate 21 using welding means.

  Here, the thickness dimension of the left front side plate 22 and the right front side plate 23 is set to be larger than the thickness dimension of the left side plate 15 and the right side plate 16 constituting the bucket base 13. Further, the left front side plate 22 and the right front side plate 23 are subjected to a quenching process in advance before being welded to the left side plate side joining end 15B of the left side plate 15 and the right side plate side joining end 16B of the right side plate 16, Its hardness is increased. Thereby, the left front side plate 22 and the right front side plate 23 have sufficient rigidity against an impact received from the ground when excavating the ground or the like using the excavation bucket 11.

  Reference numeral 24 denotes a plurality of (for example, three) excavating claws provided side by side in the left and right directions at the front end of the front bottom plate 21. Each excavation claw 24 includes an adapter 24A fixed to the front end portion of the front bottom plate 21 by means of welding or the like, and a claw member that is detachably attached to the adapter 24A using a pin or the like (not shown). 24B. Each excavation claw 24 projects forward from the front bottom plate 21 and excavates a hard ground or the like prior to the front bottom plate 21.

  Reference numeral 25 denotes a left side cutter provided on the lower end side of the left front side plate 22. The left side cutter 25 is formed in a polygonal plate shape using a steel plate material or the like, and has three bolt insertion holes 25A corresponding to the respective bolt insertion holes 22A of the left front side plate 22. The bolts 27 are inserted into the bolt insertion holes 22A of the left front plate 22 and the bolt insertion holes 25A of the left side cutter 25, and the nuts 28 are screwed into the bolts 27, whereby the left side cutter 25 is moved to the left front plate 25. It is attached to the lower end side of 22 so that attachment or detachment is possible.

  Reference numeral 26 denotes a right side cutter provided on the lower end side of the right front side plate 23. The right side cutter 26 is formed into a polygonal plate shape using a steel plate material or the like, and has three bolt insertion holes 26A corresponding to the respective bolt insertion holes 23A of the right front side plate 23. A bolt 27 is inserted into each bolt insertion hole 23A of the right front side plate 23 and each bolt insertion hole 26A of the right side cutter 26, and a nut 28 is screwed into the bolt 27, whereby the right side cutter 26 is It is attached to the lower end side of 23 so that attachment or detachment is possible.

  The left side cutter 25 and the right side cutter 26 protrude forward from the left front side plate 22 and the right front side plate 23, and excavate hard ground or the like prior to the left front side plate 22 and the right front side plate 23.

  The excavation bucket 11 according to this embodiment has the above-described configuration. Next, a procedure for manufacturing the excavation bucket 11 will be described.

  First, as shown in FIG. 3, the bucket base 13 including the bottom plate 14 and the left and right side plates 15 and 16 and the left and right brackets 19 and 20 are integrally formed using a shell mold casting method. Here, in the shell mold casting method, a molding mold of a thermosetting shell type is manufactured by applying molding sand to which a phenolic resin binder is added to a heated mold, and a casting is formed using this mold. To do.

  Thereby, the base body side integrated body 12 in which the bucket base body 13 including the bottom plate 14 and the left and right side plates 15 and 16 and the left and right brackets 19 and 20 are integrated can be cast. As a result, the shape of the bucket base 13 related to the mud sweeping property can be freely formed by casting, and the mud sweeping property of the excavation bucket 11 can be improved.

  On the other hand, since the base-side integrated body 12 does not include the front bottom plate 21, the left front-side plate 22, and the right front-side plate 23, the outer shape of the base-side integrated body 12 can be kept small, and the scale of the casting equipment is reduced. be able to. As a result, the scale of the casting facility can be reduced as compared with the case where the entire excavation bucket 11 including the front bottom plate 21, the left front plate 22, and the right front plate 23 is cast. As a result, it is possible to manufacture the excavation bucket 11 with good mud sweepability while reducing the manufacturing cost.

  Next, as shown in FIGS. 3 and 4, the front bottom plate 21 whose hardness has been increased by pre-quenching the bottom plate-side joining end 14 </ b> F of the bottom plate 14 constituting the substrate-side integrated body 12 is welded. In this case, as shown in FIG. 6, a bottom plate side groove 14 </ b> G that is inclined toward the outer surface 14 </ b> E of the bottom plate 14 is provided at the bottom plate side joining end 14 </ b> F. As a result, a good weld bead 29 can be formed at the joint between the bottom plate side groove 14G and the front bottom plate 21, and the bonding strength between the base-side integrated body 12 and the front bottom plate 21 can be increased.

  On the other hand, the left front plate 22, which has been hardened in advance by welding, is welded to the left side plate-side joining end 15 </ b> B of the left side plate 15 that constitutes the base-side integrated object 12, and the right-side that constitutes the base-side integrated object 12. The right front side plate 23 whose hardness has been increased by pre-quenching is welded to the right side plate side joint end 16B of the plate 16. In this case, as shown in FIG. 7, a left side plate side groove 15 </ b> C that is inclined toward the outer surface 15 </ b> D of the left side plate 15 is provided at the left side plate side joint end 15 </ b> B. As a result, a good weld bead 30 can be formed at the joint between the left side plate side groove 15 </ b> C and the left front side plate 22. Further, the right side plate side joint end 16B is also provided with a right side plate side groove (not shown) similar to the left side plate side groove 15C, and is good for the joint between the right side plate side joint end 16B and the right front side plate 23. A weld bead 30 can be formed. Accordingly, it is possible to increase the bonding strength between the base-side integrated body 12 and the left front plate 22 and to increase the bonding strength between the base-side integrated body 12 and the right front plate 23.

  In this way, as shown in FIG. 4, the bucket base 13 and the left and right brackets 19 and 20 are individually formed using the steel plate material on the base-side integrated body 12 integrally formed by casting. The front bottom plate 21, the left front side plate 22, and the right front side plate 23 can be joined using welding means.

  Next, as shown in FIG. 5, the adapter 24A of the excavation claw 24 is fixed to the front end portion of the front bottom plate 21 by means of welding or the like, and the claw member 24B is attached to the adapter 24A. On the other hand, the left side cutter 25 is attached to the lower end side of the left front plate 22 using bolts 27 and nuts 28, and the right side cutter 26 is attached to the lower end side of the right front plate 23 using bolts 27 and nuts 28.

  As a result, as shown in FIG. 2, the front bottom plate 21, the left front plate 22, and the right front plate 23 are welded to the base unit integrated body 12 including the bucket base 13 and the left and right brackets 19 and 20 by means such as welding. A plurality of excavation claws 24 are attached to the front end portion of the front bottom plate 21 and the excavation bucket 11 is attached to the lower ends of the left and right front plates 22 and 23 and the left and right side cutters 25 and 26 are attached. Can be manufactured.

  Thus, according to the present embodiment, the bucket base 13 composed of the bottom plate 14 and the left and right side plates 15 and 16 and the pair of brackets 19 and 20 provided on the upper front end 14B side of the bottom plate 14 are cast by the base. The excavation bucket 11 is manufactured by joining the front bottom plate 21 and the left and right front plates 22 and 23 that are individually formed to the base-side unit 12 by welding. can do. Thereby, since the shape of the bucket base | substrate 13 can be freely formed by casting, the mud sweeping property of the excavation bucket 11 can be improved.

  Further, the whole excavation bucket 11 including the front bottom plate 21 and the left and right front plates 22 and 23 is cast by casting the base-side integrated body 12 constituted by the bucket base 13 and the pair of brackets 19 and 20. Compared to the case, the scale of the casting equipment can be reduced. As a result, it is possible to manufacture the excavation bucket 11 with good mud sweepability while reducing the manufacturing cost.

  On the other hand, the front bottom plate 21 and the left and right front plates 22 and 23 are preliminarily subjected to a quenching process in a previous stage of joining to the substrate side integrated body 12. As a result, the front bottom plate 21 and the left and right front side plates whose hardness has been increased can be joined to the base-side integrated body 12, and the durability of the excavation bucket 11 can be increased. Moreover, after the excavation bucket 11 is manufactured by quenching the front bottom plate 21 and the left and right front side plates 22 and 23 having a small outer shape, the front bottom plate 21 of the excavation bucket 11 and the left and right fronts are manufactured. Compared with the case where the side plates 22 and 23 are subjected to a quenching process, the waste of the quenching operation can be eliminated and the workability can be improved.

  In addition, the bottom plate 14 of the substrate-side integrated body 12 is provided with a bottom plate-side groove 14G at the bottom-plate-side bonding end 14F bonded to the front bottom plate 21, and the left-side plate 15 of the substrate-side integrated body 12 is connected to the left front plate 22. A left side plate-side groove 15C is provided at the left side plate-side joint end 15B to be joined, and the right side plate 16 of the substrate-side integrated body 12 is provided with a right side plate-side joint end 16B joined to the right front side plate 23. A right side plate side groove similar to the tip 15C is provided.

  Thereby, when joining the base-body-side object 12 and the front bottom plate 21 by welding, a good weld bead 29 is provided between the bottom plate-side groove 14G provided at the bottom plate-side joining end 14F and the front bottom plate 21. It can be formed, and the bonding strength between the substrate-side monolith 12 and the front bottom plate 21 can be increased. On the other hand, when joining the base-side unit 12 and the left and right front plates 22 and 23 by welding, between the left plate side groove 15C and the left front plate 22 provided at the left plate side joining end 15B. A good weld bead 30 can be formed between the right-side plate-side groove provided on the right-side plate-side joining end 16B and the right-front side plate 23, and the base-side integrated body 12 and the left and right front-side plates 22, 23 can be formed. The joint strength can be increased.

  In this case, the bottom plate side joint end 14F, the left side plate side joint end 15B, and the right side plate side joint end 16B of the base body side integrated body 12 are respectively casted into the bottom plate side groove 14G, the left side plate side groove 15C, and the right side by casting. A plate-side groove can be formed. This eliminates the need to post-process the bottom plate side groove 14G, the left side plate side groove 15C, and the right side plate side groove with respect to the bottom plate side joint end 14F, the left side plate side joint end 15B, and the right side plate side joint end 16B. In addition, the manufacturing cost of the substrate-side monolith 12 can be reduced.

  Next, FIG. 8 thru | or 13 shows the 2nd Embodiment of this invention, The characteristics of 2nd Embodiment were formed using the front bottom board formed using the casting, and the steel plate material. In other words, the left and right front plates are joined to the base-side unit. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  31 shows the excavation bucket according to the second embodiment, the excavation bucket 31 is a base-side integrated object 12 in which the bucket base 13 and the left and right brackets 19 and 20 are integrally formed using casting means, It is comprised by the below-mentioned front bottom board 32 formed using the casting, the below-mentioned left front side board 34 formed using the steel plate material, and the right front side board 35.

  Reference numeral 32 denotes a front bottom plate provided at the lower front end 14A of the bottom plate 14 constituting the bucket base 13. The front bottom plate 32 is used in the second embodiment in place of the front bottom plate 21 according to the first embodiment. Is. Here, the front bottom plate 32 has a substantially rectangular shape extending in the left and right directions, the edge portion 32A joined by welding to the lower front end 14A of the bottom plate 14, and the front end portion of the edge portion 32A in the left and right directions. It consists of three wedge-shaped claw portions 32B arranged side by side and protruding forward from the edge portion 32A, and is integrally formed using cast iron or cast steel.

  In this case, the thickness dimension of the edge portion 32A of the front bottom plate 32 is set to be equal to the thickness dimension of the lower front end 14A of the bottom plate 14. Further, both left and right ends of the edge portion 32A are a left bent portion 32C and a right bent portion 32D which are bent upward, respectively, and the upper end portion of the left bent portion 32C is welded to the lower end portion of a left front side plate 34 which will be described later. The upper end portion of the right bent portion 32D is welded to the lower end portion of the right front side plate 35 described later.

  Here, the edge part joined to the lower front end 14A of the bottom plate 14 in the edge portion 32A becomes a front bottom plate side joint end 32E, and the front bottom plate side joint end 32E is opened to the front bottom plate side joint end 32E as shown in FIG. A tip 32F is formed. The front bottom plate side groove 32F is inclined from the edge of the front bottom plate side joint end 32E toward the outer surface 32G of the front bottom plate 32, and the groove angle θ3 of the front bottom plate side groove 32F is set to 45 °, for example. Has been. Thus, a V-shaped groove is formed between the bottom plate side groove 14G formed at the bottom plate side joint end 14F of the bottom plate 14 and the front bottom plate side groove 32F formed at the front bottom plate side joint end 32E of the front bottom plate 32. Can be formed. Therefore, by welding at the position of the V-shaped groove, the bottom plate side joining end 14F of the bottom plate 14 and the front bottom plate side joining end 32E of the front bottom plate 32 are melted over the entire plate thickness, and the bottom plate side opening is performed. A good weld bead 33 can be formed at the joint between the tip 14G and the front bottom plate side joining end 32E, and the joining strength between the base-side integrated body 12 and the front bottom plate 21 can be increased.

  In this case, the front bottom plate side groove 32F is not formed by performing post-processing such as cutting on the front bottom plate side joint end 32E, but is formed when the front bottom plate 32 is cast. In addition, the hardness of the front bottom plate 32 is increased by performing a quenching process in advance before the front bottom plate 32 is welded to the bottom plate-side joining end 14F of the bottom plate 14.

  Reference numeral 34 denotes a left front side plate provided at the front end 15 </ b> A of the left side plate 15 constituting the bucket base 13. The left front side plate 34 is formed in a substantially rectangular flat plate shape that extends upward and downward using a steel plate material, and three bolt insertion holes 34A are formed on the lower end side thereof. Here, the thickness dimension of the left front side plate 34 is set to be larger than the thickness dimension of the left side plate 15, and the left front side plate 34 includes the left side plate side joint end 15 </ b> B of the left side plate 15 and the left bent portion 32 </ b> C of the front bottom plate 32. It joins to the upper end part of this using a welding means.

  Reference numeral 35 denotes a right front side plate provided at the front end 16 </ b> A of the right side plate 16 constituting the bucket base 13. The right front side plate 35 is formed in a substantially rectangular flat plate shape that extends upward and downward using a steel plate material, and three bolt insertion holes 35A are formed on the lower end side thereof. Here, the thickness dimension of the right front side plate 35 is set larger than the thickness dimension of the right side plate 16, and the right front side plate 35 includes the right side plate side joint end 16 </ b> B of the right side plate 16 and the right bent portion 32 </ b> D of the front bottom plate 32. It joins to the upper end part of this using a welding means.

  In this case, as shown in FIG. 13, the left side plate side groove 15 </ b> C is provided at the left side plate side joint end 15 </ b> B so as to incline toward the outer surface 15 </ b> D of the left side plate 15. A good weld bead 36 can be formed at the joint with the left front plate 34. Further, the right side plate side joint end 16B is also provided with a right side plate side groove similar to the left side plate side groove 15C, so that a good weld bead is provided at the joint between the right side plate side groove and the right front side plate 35. 36 can be formed.

  Further, the left front plate 34 and the right front plate 35 are subjected to a quenching process in advance before being welded to the left side plate side joining end 15B of the left side plate 15 and the right side plate side joining end 16B of the right side plate 16, Its hardness is increased.

  Then, the bolts 27 are inserted into the bolt insertion holes 34A of the left front plate 34 and the bolt insertion holes 25A of the left side cutter 25, and the nuts 28 are screwed into the bolts 27. A left side cutter 25 is detachably attached. On the other hand, a bolt 27 is inserted into each bolt insertion hole 35A of the right front plate 35 and each bolt insertion hole 26A of the right side cutter 26, and a nut 28 is screwed into the bolt 27, so that the lower end side of the right front plate 35 is A right side cutter 26 is detachably attached.

  The excavation bucket 31 according to the second embodiment has the above-described configuration, and the bucket base 13 including the bottom plate 14 and the left and right side plates 15 and 16 and the left and right brackets 19 and 20 are cast. By joining the base bottom body 12 integrally formed using the means, the front bottom plate 32 formed of a casting, the left front side plate 34 and the right front side plate 35 formed of a steel plate material using welding means. The excavation bucket 31 can be manufactured.

  In this case, also in the second embodiment, similarly to the first embodiment, the shape of the bucket base 13 related to the mud sweepability can be freely formed by casting, and the mud sweep of the excavation bucket 31 can be performed. Can increase the sex. On the other hand, the base-side integrated body 12 including the bucket base 13 and the left and right brackets 19 and 20 does not include the front bottom plate 32, the left front-side plate 34, and the right front-side plate 35. Can be kept small, and the scale of the casting equipment can be reduced, so that the excavation bucket 31 with good mud sweepability can be manufactured while reducing the manufacturing cost.

  Moreover, according to the second embodiment, since the front bottom plate side groove 32F is formed at the front bottom plate side joint end 32E of the front bottom plate 32 at the time of casting, it is formed at the bottom plate side joint end 14F of the bottom plate 14. A V-shaped groove can be formed between the bottom plate side groove 14G thus formed and the front bottom plate side groove 32F formed at the front bottom plate side joint end 32E of the front bottom plate 32. Therefore, by performing welding at the position of the V-shaped groove, a good weld bead 33 can be formed between the bottom plate side joining end 14F of the bottom plate 14 and the front bottom plate side joining end 32E of the front bottom plate 32. The joining strength between the bottom plate 14 and the front bottom plate 32 can be increased.

  Next, FIG. 14 thru | or 18 shows the 3rd Embodiment of this invention, and the characteristics of 3rd Embodiment were formed using the front bottom board formed using the steel plate material, and casting. In other words, the left and right front plates are joined to the base-side unit. Note that in the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  41 shows the excavation bucket by 3rd Embodiment, This excavation bucket 41 was formed using the base | substrate side integrated object 12 which consists of the bucket base | substrate 13, and the left and right brackets 19 and 20, and a steel plate material. It is comprised by the below-mentioned front bottom board 42 and the below-mentioned left front side board 44 and the right front side board 46 which were formed using casting.

  Reference numeral 42 denotes a front bottom plate provided at the lower front end 14A of the bottom plate 14 constituting the bucket base 13. The front bottom plate 42 is formed in a rectangular flat plate shape that extends left and right using a steel plate material, and the thickness dimension of the front bottom plate 42 is set to be larger than the thickness dimension of the lower front end 14A of the bottom plate 14. Yes.

  Further, the hardness of the front bottom plate 42 is increased by performing a quenching process in advance before the front bottom plate 42 is welded to the bottom plate side joint end 14F of the bottom plate 14. The front bottom plate 42 is joined to the bottom plate-side joining end 14F of the bottom plate 14 using welding means. In this case, as shown in FIG. 17, since the bottom plate side groove 14G is provided at the bottom plate side joint end 14F of the bottom plate 14, a good weld bead is formed at the joint portion between the bottom plate side groove 14G and the front bottom plate 42. 43 is formed so that the bonding strength between the substrate-side integrated body 12 and the front bottom plate 42 can be increased.

  On the other hand, the adapter 24A of each excavation claw 24 is fixed to the front end portion of the front bottom plate 42 by means of welding or the like, and the claw member 24B can be attached to and detached from these adapters 24A using pins or the like (not shown). Installed.

  Reference numeral 44 denotes a left front side plate provided at the front end 15 </ b> A of the left side plate 15 constituting the bucket base 13. The left front side plate 44 has a flat plate shape extending in the upward and downward direction, a left edge portion 44A joined by welding to the left side plate side joining end 15B of the left side plate 15, and a left edge portion 44A disposed on the lower end side of the left edge portion 44A. It consists of a rectangular left cutter portion 44B protruding forward from the edge portion 44A, and is integrally formed using cast iron or cast steel.

  In this case, the thickness dimension of the left edge portion 44 </ b> A of the left front side plate 44 is set equal to the thickness dimension of the left side plate 15. Of the left edge portion 44A, an edge portion joined to the front end 15A of the left side plate 15 becomes a left front side plate side joining end 44C, and as shown in FIG. 18, the left front side plate side joining end 44C has a left front side plate side groove 44D. Is formed. The left front plate side groove 44D is inclined from the end edge of the left front plate side joint end 44C toward the outer surface 44E of the left front plate 44, and the groove angle θ4 of the left front plate side groove 44D is set to 45 °, for example. Has been. As a result, there is a difference between the left side plate side groove 15C formed at the left side plate side joint end 15B of the left side plate 15 and the left front side plate side groove 44D formed at the left front side plate side joint end 44C of the left front side plate 44. A groove can be formed, and a good weld bead 45 can be formed at the joint between the left side plate side joint end 15B and the left front side plate side joint end 44C. It is the structure which can raise the joining strength of.

  Reference numeral 46 denotes a right front side plate provided at the front end 16 </ b> A of the right side plate 16 constituting the bucket base 13. Like the left front plate 44, the right front plate 46 includes a right edge portion 46A and a right cutter portion 46B, and is integrally formed using cast iron or cast steel.

  In this case, the thickness dimension of the right edge portion 46 </ b> A of the right front side plate 46 is set equal to the thickness dimension of the right side plate 16. The edge portion joined to the front end 16A of the right side plate 16 in the right edge portion 46A is a right front side plate side joining end 46C, and the right front side plate is similar to the left front side plate side joining end 44C. A side groove is formed. Accordingly, a V-shaped opening is formed between the right side plate side groove formed at the right side plate side joint end 16B of the right side plate 16 and the right front side plate side groove formed at the right front side plate side joint end 46C of the right front side plate 46. The tip can be formed, a good weld bead 45 can be formed at the joint between the right side plate side joint end 16B and the right front side plate side joint end 46C, and the base side unit 12 and the right front side plate 46 are joined. The structure can increase the strength.

  The excavation bucket 41 according to the third embodiment has the above-described configuration, and as in the first embodiment, the shape of the bucket base 13 related to the mud sweepability can be freely formed by casting. It is possible to improve the mud sweepability of the excavation bucket 41. On the other hand, the base-side integrated body 12 including the bucket base 13 and the left and right brackets 19 and 20 does not include the front bottom plate 42, the left front-side plate 44, and the right front-side plate 46. Thus, the scale of the casting equipment can be reduced, and the excavation bucket 41 with good mud sweepability can be manufactured while reducing the manufacturing cost.

  Moreover, according to the third embodiment, the left front plate side groove 44 </ b> D formed at the left front plate side joint end 44 </ b> C of the left front side plate 44 and the left side plate side formed at the left side plate side joint end 15 </ b> B of the left side plate 15. A V-shaped groove can be formed between the groove 15C and the right front plate side groove formed on the right front plate side joint end 46C of the right front plate 46 and the right plate side joint end 16B of the right plate 16. A V-shaped groove can be formed between the groove on the right side plate side. Therefore, by performing welding at the position of the V-shaped groove, the bonding strength between the left side plate 15 and the left front side plate 44 and the bonding strength between the right side plate 16 and the right front side plate 46 can be increased.

  Next, FIGS. 19 to 22 show a fourth embodiment of the present invention. The features of the fourth embodiment are a front bottom plate formed using a casting and a left formed using a casting. The right front plate is joined to the base body-side unit. Note that in the fourth embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  Reference numeral 51 denotes a digging bucket according to the fourth embodiment. The digging bucket 51 is formed by using a casting body and a base-side unitary body 12 including a bucket base 13 and left and right brackets 19 and 20. The front bottom plate 52, and a left front plate 54 and a right front plate 56, which will be described later, are formed using a casting.

  Reference numeral 52 denotes a front bottom plate provided at the lower front end 14 </ b> A of the bottom plate 14 constituting the bucket base 13. The front bottom plate 52 has a substantially rectangular shape extending in the left and right directions. The edge portion 52A is joined to the lower front end 14A of the bottom plate 14 by welding, and is aligned in the left and right directions at the front end portion of the edge portion 52A. It consists of three projecting claw portions 52B and is integrally formed using cast iron or cast steel. In this case, the thickness dimension of the edge portion 52A of the front bottom plate 52 is set to be equal to the thickness dimension of the lower front end 14A of the bottom plate 14. Further, both left and right end sides of the edge portion 52A are a left bent portion 52C and a right bent portion 52D, which are bent upward.

  Here, the edge part joined to the lower front end 14A of the bottom plate 14 in the edge portion 52A becomes a front bottom plate side joint end 52E, and as shown in FIG. 21, the front bottom plate side joint end 52E has a front bottom plate side opening. A tip 52F is formed. The front bottom plate side groove 52F is inclined from the edge of the front bottom plate side joint end 52E toward the outer surface 52G of the front bottom plate 52, and the groove angle θ5 of the front bottom plate side groove 52F is set to 45 °, for example. Has been. Thus, a V-shaped groove is formed between the bottom plate side groove 14G formed at the bottom plate side joint end 14F of the bottom plate 14 and the front bottom plate side groove 52F formed at the front bottom plate side joint end 52E of the front bottom plate 52. Can be formed. Therefore, by performing welding at the position of the V-shaped groove, a good weld bead 53 can be formed at the joint between the bottom plate side joint end 14F of the bottom plate 14 and the front bottom plate side joint end 52E of the front bottom plate 52. It can be configured. In addition, the hardness of the front bottom plate 52 is increased by performing a quenching process in advance before the front bottom plate 52 is welded to the bottom plate side joint end 14F of the bottom plate 14.

  Reference numeral 54 denotes a left front side plate provided at the front end 15A of the left side plate 15 constituting the bucket base 13. The left front side plate 54 includes a left edge portion 54A joined to the left side plate side joining end 15B of the left side plate 15 by welding and a left cutter portion 54B provided on the lower end side of the left edge portion 54A. It is integrally formed using cast steel. In this case, the thickness dimension of the left edge portion 54 </ b> A of the left front side plate 54 is set equal to the thickness dimension of the left side plate 15. Of the left edge portion 54A, an edge portion joined to the front end 15A of the left side plate 15 is a left front side plate side joining end 54C. As shown in FIG. 22, the left front side plate side joining end 54C has a left front side plate side groove 54D. Is formed. The left front plate side groove 54D is inclined from the edge of the left front plate side joint end 54C toward the outer surface 54E of the left front plate 54, and the groove angle θ6 of the left front plate side groove 54D is set to 45 °, for example. Has been. As a result, V between the left side plate side groove 15C formed at the left side plate side joint end 15B of the left side plate 15 and the left front side plate side groove 54D formed at the left front side plate side joint end 54C of the left front side plate 54. A shape groove can be formed, and a good weld bead 55 can be formed at the joint between the left side plate side groove 15C and the left front side plate side groove 44D.

  Reference numeral 56 denotes a right front side plate provided at the front end 16 </ b> A of the right side plate 16 constituting the bucket base 13. Like the left front plate 54, the right front plate 56 includes a right edge portion 56A and a right cutter portion 56B, and is integrally formed using cast iron or cast steel.

  In this case, the thickness dimension of the right edge portion 56 </ b> A of the right front side plate 56 is set to be equal to the thickness dimension of the right side plate 16. The edge part joined to the front end 16A of the right side plate 16 in the right edge portion 56A becomes a right front side plate side joining end 56C, and the right front side plate similar to the left front side plate side groove 54D is also formed on the right front side plate side joining end 56C. A side groove is formed. Thus, a V-shaped opening is formed between the right side plate side groove formed at the right side plate side joint end 16B of the right side plate 16 and the right front side plate side groove formed at the right front side plate side joint end 56C of the right front side plate 56. The tip can be formed, and a good weld bead 55 can be formed at the joint between the right side plate side joining end 16B and the right front side plate side joining end 56C.

  The excavation bucket 51 according to the fourth embodiment has the above-described configuration, and as in the first embodiment, the shape of the bucket base 13 related to the mud sweepability can be freely formed by casting. It is possible to improve the mud sweeping performance of the excavation bucket 51. On the other hand, the base-side integrated body 12 including the bucket base 13 and the left and right brackets 19 and 20 does not include the front bottom plate 52, the left front-side plate 54, and the right front-side plate 56. It is possible to reduce the scale of the casting equipment while suppressing the size of the casting equipment, and it is possible to manufacture the excavation bucket 51 with good mud sweepability while reducing the manufacturing cost.

  Moreover, according to the fourth embodiment, the bottom plate side groove 14G formed at the bottom plate side joint end 14F of the bottom plate 14 and the front bottom plate side groove formed at the front bottom plate side joint end 52E of the front bottom plate 52 are provided. A V-shaped groove can be formed with respect to 52F. Accordingly, by performing welding at the position of the V-shaped groove, a good weld bead 53 can be formed between the bottom plate side joint end 14F of the bottom plate 14 and the front bottom plate side joint end 52E of the front bottom plate 52. The joining strength between the bottom plate 14 and the front bottom plate 52 can be increased.

  Further, according to the fourth embodiment, the left side plate side groove 15C formed at the left side plate side joint end 15B of the left side plate 15 and the left front side plate formed at the left front side plate side joint end 54C of the left front side plate 54. A V-shaped groove can be formed between the side groove 54D and the right side plate side groove formed at the right side plate side joint end 16B of the right side plate 16 and the right front side plate side joint end 56C of the right front side plate 56. A V-shaped groove can be formed between the groove formed on the right front plate side groove. Therefore, by performing welding at the position of the V-shaped groove, the bonding strength between the left side plate 15 and the left front side plate 54 and the bonding strength between the right side plate 16 and the right front side plate 56 can be increased.

  In the first embodiment described above, the front bottom plate 21, the left front plate 22, and the right front plate 23 are separately provided for the bottom plate 14, the left plate 15, and the right plate 16 of the bucket substrate 13 that constitutes the substrate side integrated body 12. The case where it joins to is illustrated. However, the present invention is not limited to this. For example, as in the modification shown in FIG. 23, a front plate assembly 57 in which the front bottom plate 21, the left front plate 22, and the right front plate 23 are assembled together in advance is integrated. It is good also as a structure which forms and joins this front board assembly 57 with respect to the base | substrate-side integrated object 12 using a welding means. The same applies to the second, third, and fourth embodiments.

8 Connecting Pins 11, 31, 41, 51 Excavation Bucket 12 Base Side Integrated 13 Bucket Base 14 Bottom Plate 14A Lower Front End 14B Upper Front End 14F Bottom Plate Side Joint End (Base Side Joint End)
14G groove on the bottom plate side (groove)
15 Left side plate 15B Left side plate side joining end (base side joining end)
15C left side plate groove (groove)
16 Right side plate 16B Right side plate side joining end (base side joining end)
19 Left bracket 20 Right bracket 21, 32, 42, 52 Front bottom plate 22, 34, 44, 54 Front left plate 23, 35, 46, 56 Front right plate 32E, 52E Front bottom plate side joint end 32F, 52F Front bottom plate side groove 44C , 54C Left front plate side joint end 44D, 54D Left front plate side groove 46C, 56C Right front plate side joint end 57 Front plate assembly

Claims (5)

A bucket base having a bottom plate formed in a concave curve between the lower front end and the upper front end, and left and right side plates provided on the left and right sides of the bottom plate;
A front bottom plate provided at a lower front end of the bottom plate located between the side plates of the bucket base;
A left front side plate provided at a front end of the left side plate of the bucket base;
A right front side plate provided at a front end of the right side plate of the bucket base;
In the excavation bucket comprising a pair of brackets provided on the upper front end side of the bottom plate and rotatably connected to the work machine via a connection pin,
The bucket base and the pair of brackets are integrally formed using a casting means to form a base-side integrated object,
The front bottom plate and the left and right front side plates are individually formed using a casting or a steel plate,
An excavation bucket characterized in that the front bottom plate and the left and right front side plates are joined to the base body-side unit by welding means.   2. The excavation bucket according to claim 1, wherein the front bottom plate and the left and right front side plates are joined to the base body-side unit in a state of being subjected to a quenching process for increasing hardness.   The excavation bucket according to claim 1 or 2, wherein a groove is provided at the base-side joining end joined to the front bottom plate and the front side plates, in the base-side integrated body formed using casting means. .   In the case where the front bottom plate and / or the left and right front side plates are formed using a casting, the front bottom plate and / or the left and right front side plates are joined to the base body-side unit. The excavation bucket according to claim 1, 2, or 3, wherein a groove is provided at the side joint end and / or the front plate side joint end.   A front plate assembly in which the front bottom plate and the left and right front side plates are integrally assembled in advance is formed, and the front plate assembly is joined to the base-side unit by welding means. The excavation bucket of claim | item 1, 2, 3, or 4.

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