| 摘要 |
PURPOSE:To prevent a bucket device from colliding with an obstacle during slewing, by a method wherein a sonar for detection connected to a slewing valve, adapted to reduce the rotation speed of a motor for slewing, is disposed to the side of the arm or the boom of a full slewing type back hoe. CONSTITUTION:Through-holes 13 are formed in 2 spots at the front and the rear of each of 2 sides of arm of a full slewing type back hoe, and sonars 6, which are actuated when a distance from an obstacle is reduced to a level lower than a specified value, are located in the through-holes 13. When an obstacle is present in a slewing direction in a state to slew a bucket device A and a driving platform B during a work, the sonars 6 in the arm 2 detect it prompty. In this case, a slewing valve 4 is closed to reduce the rotation speed of a stepping motor M and decrease a slewing speed, and an alarming device 5 is actuated to report an alarm to an operator. |
