| 摘要 |
In an arm for a construction machine formed as a box-shaped structural body by left and right side plates, an upper plate, a lower plate, and a rear plate, a left rear thick side plate constituting the left side plate, a right rear thick side plate constituting the right side plate, a rear thick upper plate constituting the upper plate, and a rear thick lower plate constituting the lower plate are formed by using a soft steel material having a large plate thickness. A left front thin side plate constituting the left side plate, a right front thin side plate constituting the right side plate, a front thin upper plate constituting the upper plate, and a front thin lower plate constituting the lower plate are formed by using a high tensile steel material having a small plate thickness. As a result, the weight of the entire arm can be reduced. |
| 主权项 |
1. An arm for a construction machine formed as a box-shaped structural body having a square cross section by a left side plate (12), a right side plate (13), an upper plate (14) joined to upper end sides of said left and right side plates (12, 13) by welding, a lower plate (15) joined to lower end sides of said left and right side plates (12, 13) by welding, and a rear plate (16) joined to rear end sides of said left and right side plates (12, 13) and a rear end side of said upper plate (14) by welding, in which
a boom connecting boss (17) located on rear part lower sides of said left and right side plates (12, 13) and joined to rear ends of said left and right side plates (12, 13) and said lower plate (15) and a front end of said rear plate (16) by welding is provided, and a pair of left and right arm cylinder brackets (22) joined to an outer surface of said rear plate (16) by welding are provided, characterized in that: said left side plate (12) is formed by joining two members, that is, a left rear thick side plate (12A) located on a rear side where said boom connecting boss (17) is joined and made of a soft steel material with a large plate thickness and a left front thin side plate (12B) located on a front side of said left rear thick side plate (12A) and made of a high tensile steel material with a small plate thickness; said right side plate (13) is formed by joining two members, that is, a right rear thick side plate (13A) located on the rear side where said boom connecting boss (17) is joined and made of a soft steel material with a large plate thickness and a right front thin side plate (13B) located on the front side of said right rear thick side plate (13A) and made of a high tensile steel material with a small plate thickness; said upper plate (14) is formed by joining two members, that is, a rear thick upper plate (14A) located on the rear side where said rear plate (16) is joined and made of a soft steel material having a large plate thickness and a front thin upper plate (14B) located on the front side of said rear thick upper plate (14A) and made of a high tensile steel material having a small plate thickness; said lower plate (15) is formed by joining two members, that is, a rear thick lower plate (15A) located on the rear side where said boom connecting boss (17) is joined and made of a soft steel material having a large plate thickness and a front thin lower plate (15B) located on the front side of said rear thick lower plate (15A) and made of a high tensile steel material having a small plate thickness; and said rear plate (16) is formed by using a soft steel material having a large plate thickness. |
