Work implement of hydraulic excavator and method of manufacturing work implement of hydraulic excavator

Patent metadata

Field	Value
Publication number	US-2019112779-A1
Application number	US-201716090642-A
Country	US
Kind code	A1
Filing date	Jun 15, 2017
Priority date	Jun 27, 2016
Publication date	Apr 18, 2019
Grant date	—

Abstract

The number of steps required for a welding operation of a work implement of a hydraulic excavator is reduced while the welding quality is improved. A boom includes a top plate, a left side plate joined to the top plate, and a boom foot bracket. The boom foot bracket includes an extending portion. The extending portion includes a portion that faces a side surface of the top plate.

First claim

1 . A work implement of a hydraulic excavator, the work implement comprising:
a first plate material; a second plate material joined to the first plate material; a third plate material joined to the first plate material and facing the second plate material at a distance from the second plate material; and a fourth plate material joined to the second plate material and the third plate material and facing the first plate material at a distance from the first plate material, the first plate material, the second plate material, the third plate material, and the fourth plate material being joined to one another to form a box-shaped structure body, the work implement further comprising a first attachment member joined to each of the first plate material, the second plate material, the third plate material, and the fourth plate material at an end of the box-shaped structure body in a longitudinal direction of the box-shaped structure body, the first attachment member including an extending portion that extends in the longitudinal direction of the box-shaped structure body, the extending portion including a portion that faces a side surface of the first plate material.

2 . The work implement of a hydraulic excavator according to claim 1 , wherein a cutout portion is provided in a portion of the first plate material that faces the extending portion.

3 . The work implement of a hydraulic excavator according to claim 2 , wherein
the first plate material includes
a first surface that forms an outer surface of the box-shaped structure body, and
a first back surface on an opposite side of the first surface,
a portion of the first attachment member that faces the first back surface is provided with a groove preparation surface that forms a groove together with the first back surface, and a portion of the side surface that includes the cutout portion in the first plate material and a bottom portion of the groove are continuous with each other when seen from a direction perpendicular to the first surface.

4 . The work implement of a hydraulic excavator according to claim 2 , wherein the cutout portion is formed in the longitudinal direction of the box-shaped structure body so as to extend from an end of the first plate material beyond a leading end of the extending portion in the longitudinal direction.

5 . The work implement of a hydraulic excavator according to claim 1 , wherein the extending portion has a bank shape formed such that a protrusion height decreases toward a leading end of the extending portion in the longitudinal direction.

6 . The work implement of a hydraulic excavator according to claim 1 , wherein the first attachment member is a cast product.

7 . A method of manufacturing a work implement of a hydraulic excavator, the work implement including:
a first plate material; a second plate material joined to the first plate material; a third plate material joined to the first plate material and facing the second plate material at a distance from the second plate material; and a fourth plate material joined to the second plate material and the third plate material and facing the first plate material at a distance from the first plate material, the first plate material, the second plate material, the third plate material, and the fourth plate material being joined to one another to form a box-shaped structure body, the work implement further including a first attachment member joined to each of the first plate material, the second plate material, the third plate material, and the fourth plate material at an end of the box-shaped structure body in a longitudinal direction of the box-shaped structure body, the first attachment member including an extending portion that extends in the longitudinal direction of the box-shaped structure body, the extending portion including a portion that faces a side surface of the first plate material, the method comprising: forming a recess portion as a partial recess in a surface of the first attachment member, the recess portion being located between the extending portion and the side surface of the first plate material that faces the extending portion; and filling up the recess portion by welding.

Assignees

• Komatsu Mfg Co Ltd

Inventors

• Utou Shinpei
• Asada Tsuyoshi
• Sugihara Nobuyasu
• Kunisawa Naohiro
• Nakatani Yuki
• Ueno Masashi

Classifications

• E02F3/32

  working downwardly and towards the machine, e.g. with backhoes · CPC title

• E02F9/14

  Booms {only for booms with cable suspension arrangements (for booms or manipulators with cable suspensions for suction pipes E02F3/905 takes precedence; for booms per se E02F3/38; E02F3/34 for bucket-arms)}; Cable suspensions · CPC title

• E02F3/382 Primary

  Connections to the frame; Supports for booms or arms (devices to connect booms or arms to tractors or similar machines E02F3/627; pivot joint assemblies in particular E02F9/006) · CPC title

• E02F3/38 Primary

  Cantilever beams {, i.e. booms;, e.g. manufacturing processes, forms, geometry or materials used for booms (for booms with cable suspension arrangements E02F9/14 takes precedence)}; Dipper-arms {, e.g. manufacturing processes, forms, geometry or materials used for dipper-arms}; Bucket-arms {(E02F3/34 takes precedence)} · CPC title

• E02F9/0816 Primary

  Welded frame structure · CPC title