| 摘要 |
PROBLEM TO BE SOLVED: To automatically disengage the tooth and the claw part of a cab fall prevention device from each other. SOLUTION: A first pilot check valve 16 and a second pilot check valve 17 are provided to intervene respectively in the rising side oil passage 11 and the falling side oil passage 12 of a tilt cylinder device 3 and the stay of the cab fall prevention device is pivotally attached to the piston rod 4 of the tilt cylinder device 3. A fall prevention member for engagement with the stay is fixed to a cylinder 5. A disengagement cylinder device 30 for disengaging the claw part of the fall prevention member from the tooth of the stay is installed at the cylinder 5 and a disengagement oil passage 37 in the cylinder chamber 32 of the cylinder device 30 is connected to the primary port 62 side of the second pilot check valve 17 and a throttle 39 is provided between the branching point of the oil passage 37 and the second pilot check valve 17. The disengagement cylinder device can automatically cancel a condition under which the fall of the cab is prevented, and a cab can be stopped while it is tilted forward beyond a fulcrum during a tilt-up operation. |
