| 摘要 |
PROBLEM TO BE SOLVED: To easily recognize that a large collision energy acts on steering cylinders by reducing traveling performance of a traveling body in a case of operating a pressure of a prescribed value or more on the steering cylinder. SOLUTION: When left/right ununiform impact acts on steering cylinders 26, 27 and a pressure of a prescribed value or more acts thereon, a shuttle valve 29 is shifted by the pressure from bottom chambers 26a, 27a or rod chambers 26b, 27b of the steering cylinders 26, 27 and a pressure switch 30 is turned on. A first relay 32 and a second relay 33 are tuned on and a solenoid valve 37 is excited so that pressure oil discharged from an oil pressure source is fed to the bottom chambers of the cylinders. The output of an engine is reduced, oil quantity discharged from the oil pressure pump is reduced, and rotation speed of the oil pressure motor is reduced so that the traveling speed of the traveling body is reduced. This constitution allows a driver to recognize that some abnormality occurs in the steering without any change in outer appearance of the traveling body. |
