| 摘要 |
A parking brake control device of wheel type heavy construction equipment is provided to prevent accidents caused by unintended movement by releasing a parking brake while a traveling lever puts on the neutral position only. The parking brake control device of wheel type heavy construction equipment for keeping a parking brake at the parking state all the time comprises a hydraulic pump supplying pressure oil to a parking brake through a parking brake line, a parking brake(12) releasing the parking state of equipment with pressure oil supplied from the hydraulic pump and parking equipment with the force of a spring(12A) with no supply of pressure oil, and a parking brake control valve(10) connected to a parking brake line connecting the parking brake and the hydraulic pump to supply pressure oil or cut off the supply of pressure oil from the hydraulic pump to the parking brake and composed of a solenoid valve provided with a solenoid valve section(10A), wherein a parking switch(15) is connected to the solenoid valve section of the parking brake control valve by a primary relay(20), a secondary relay(30) and a third relay(40) which send electric currents to input terminals(21,31,41) and output terminals(23,33,43) if an electric current is supplied through a neutral signal line by putting a traveling lever(13) on the neutral position(N). |
