| 摘要 |
PURPOSE:To prevent the damage of an unfolding blade, by a method wherein a device is constituted such that rotation of the expanding blade and a rotary angle, detected by a rotary angle detector secured to an equalizer link, are approximately in proportional relationship according to a primary function. CONSTITUTION:By expanding a hydraulic cylinder 23 as a bottom spreading bucket 11 is rotated, an unfolding blade 20 is rotated around a hinge 21 to unfold the blade outwardly. Additionally, since a B link 44 is rotated through an A link 43 of an equalizer depending upon the folding and unfolding condition of the unfolding blade 20, the unfolding and folding amount of the unfolding blade 20 is detected by a rotary angle detector 25. When an earth guide wall 20a is also withdrawn from a case 14 along with rotation of the unfolding blade 20, a main scraper 26, simultaneously, is also opened to form a space G into which earth flows, and excavated earth is guided by the unfolding blade 20 and the earth guide wall 20a to contain the earth in the case 14. This enables an operator to know the operating condition of the unfolding blade 20, resulting in prevention of breakdown of the unfolding blade 20. |
