SAFETY DEVICE OF HIGH LIFT WORK VEHICLE

PROBLEM TO BE SOLVED: To provide a safety device of a high lift work vehicle capable of grasping the load on a sub boom of a temporary supporting device in a correct state, and preventing, based on the grasped load, breakage of the temporary supporting device and the toppling of a car. SOLUTION: The horizontal load Fx in the derricking plane along the derricking plane of a sub boom 55 applied to a fore-end part (a load application point 56a) of the sub boom 55 while holding a cable by a cable holder 56 is detected by an in-derricking-plane horizontal load detector 82. The horizontal load Fy outside the derricking plane orthogonal to the derricking plane of the sub boom 55 is detected by an outside-derricking-plane horizontal load detector 83. The vertical load Fz applied to a fore-end of the sub boom 55 is detected by a vertical load detection means 90. When at least one of the horizontal load Fx in the derricking plane, the horizontal load Fy outside the derricking plane, and the vertical load Fz exceeds the allowable values Fxa, Fya and Fza set corresponding to each load, the operation of the sub boom 55 and the operation a main boom 30 are regulated. COPYRIGHT: (C)2007,JPO&INPIT