Safety securing system for operation lever of construction vehicle

1. A safety securing system for an operation lever of a construction vehicle, in which the construction vehicle includes a plurality of work equipments, each being driven by a hydraulic pump operating by an engine, an operation lever for generating a driving signal for the work equipments, and a safety lever for stopping the operation lever when the safety lever is locked out, the safety securing system comprising:

a receiver for receiving a detection signal from an engine rpm detector detecting the engine shaft rpm, a control input detector of the operation lever, and a safety lever position detector, respectively;

a data processor for deciding, on the basis of the signals received by the receiver, whether the engine starts, whether the operation lever is in the neutral position, and whether the safety lever is in operation, making a decision on whether to operate the work equipment, and memorizing, through a neutral position check bit of the data processor, whether the decision on the position of the operation lever is made; and

an output for outputting, based on the result of process of the data processor, an engine stop signal, an alarm signal, and a driving signal outside according to the operation lever's control input.

2. The system according to claim 1 , wherein if the operation lever is not in the neutral position while the engine stops running, the safety securing system for the operation lever outputs an engine stop signal and an alarm signal; if the safety lever is in operation when the engine starts, the safety securing system turns off the neutral position check bit; if the engine starts and the security lever is released and the neutral position check bit is turned off, the safety securing system outputs an engine stop signal and an alarm message provided that the operation lever is not in the neutral position, and the safety securing system changes the value of the neutral position check bit to ‘on’ provided that the operation lever is in the neutral position; and if the engine starts and the security lever is released and the neutral position check bit is ‘on’, the safety securing system outputs a driving signal according to the control input of the operation lever provided that a signal from the operation lever is normal, and the safety securing system outputs an alarm message provided that a signal from the operation lever is abnormal.