Safety device for a construction machine

A safety device for a construction machine provided with a front working device, the safety device comprising:

• operating levers configured to provide operating instructions to the front working device:
• a gate locking switch section that detects when an operation position of a gate lock lever is in a lock position in which the gate lock lever disables the operating instructions from the operating levers of the construction machine so that the front work device cannot be driven and when the operation position of the gate lock lever is in a lock release position, the gate lock lever enables the operating instructions from the operating levers of the construction machine so that the front work device is drivable;
• seat belt switch section that outputs a signal corresponding to a wearing state of a seat belt provided on the construction machine:
• a tilting angle sensor for detecting a tilting state of the construction machine;
• a warning lamp and a speaker that issues a warning about the seat belt to an operator of the construction machine;
• and
• a controller that is connected to the gate locking switch, the tilting angle sensor, the warning lamp, the speaker, and the seat belt switch section, wherein the controller:
• detects, based on a signal from the seat belt switch, whether or not the seat belt is worn by the operator;
• detects, based on a signal from the gate locking switch section, that the gate lock lever is in the lock position or in the lock release position;
• detects, based on a signal from the tilting angle sensor, whether or not the construction machine is tilted with respect to the horizontal plane, and wherein
• when the controller detects that the seat belt is not worn by the operator and the operation position of the gate lock lever is in the lock position, the controller gives a first warning that turns on the warning lamp;
• when the controller detects that the seat belt is not worn by the operator and that the operation position of the gate lock lever is in the lock release position and the construction machine is not tilted with respect to the horizontal plane, the controller gives a second warning with an attention arousing performance that is higher than that of the first warning and flickers the warning lamp;
• and
• when the controller detects that the seat belt is not worn by the operator, that the operation position of the gate lock lever is in the lock release position, and that the construction machine is tilted with respect to the horizontal plane, the controller gives a third warning with an attention arousing performance that is higher than that of the second warning, flickers the warning lamp, and outputs a warning sound from the speaker with a sound volume of the warning sound that increases as the tilting state becomes larger.