| 摘要 |
PURPOSE:To prevent contacting of a working equipment with a vehicle body, by a method wherein, in an excavator equipped with two booms, when an angle, formed with one boom and the other boom, and an angle, formed with the other boom and an arm, attain a given angle, control valves for the arm and the other boom are returned to a neutral position. CONSTITUTION:A second boom 1 is pivotably connected to a first boom 2, an arm 3 to the second boom 2, and a bucket 4 to the arm 3. A parallel 4-kunckle link Lp consists of rod materials L1-L4, a coupling A is positioned at the connection of the boom 1 to the boom 2, a coupling B at the connection of the boom 2 to the arm 3, and a coupling C at the given location of the arm 3. As a result, the shape of the link Lp changes resulting from the rotation of the arm 3. In case the sum of the angle alpha, formed with said boom 1 and the boom 2, and the angle beta, formed with the boom 2 and the arm 3, are reduced to less than a given angle, the control valves for the boom 2 and the arm 3 are returned to a neutral position by means of limit switches 5 and 6. |
