Abstract: The present invention provides a construction machine adopting a structure that assures a predetermined sound pressure level along a forward direction relative to the construction machine and allows a warning horn to be miniaturized. Warning horns 12 and 13 are mounted in the vicinity of at least either a left headlamp 9 or a right headlamp 10 provided on the left side and the right side of a vehicle body 3 of the construction machine. The warning horns 12 and 13 are housed inside a bracket 11 used to mount the headlamp 9 or 10. The plurality of warning horns 12 and 13 are disposed on a single side toward the left headlamp 9 or the right headlamp 10. Since a front attachment 7 does not block the sound generated from the warning horns 12 and 13 and thus the warning sound can travel without hindrance along the forward direction, a predetermined sound pressure level is achieved with ease along the forward direction relative to the vehicle body 3.

Abstract: Control valves are respectively provided in a pair of variable displacement hydraulic pumps. If an ultra low speed travel signal is issued in response to an ultra-low-speed switch turned on, one of the control valves is fixed to a neutral position by a solenoid valve. And a displacement amount of a travel motor is fixed at a maximum displacement by another solenoid valve. In this way, an upper limit for motor rotation speed is significantly reduced. As a result, it is possible to realize the ultra low speed travel with maximum operation of an accelerator pedal, without the need for subtle operation of the accelerator pedal.

Abstract: A brake release unit is provided between a transmission control unit for controlling a transmission and a clutch device. Pressure oil supplied from a hydraulic pressure source to the clutch device is also guided to an accumulator of the brake release unit. When the engine is stopped, pressure oil from the clutch device is collected in a reservoir, and the transmission operates as a parking brake. Pressure oil accumulated in the accumulator is kept as it is. If a solenoid switching valve of the brake release unit is driven as a result of operation of a switch in the operator's cabin, pressure oil accumulated in the accumulator is supplied to the clutch device. As a result, it is possible to easily release the parking brake.

Abstract: Control valves are respectively provided in a pair of variable displacement hydraulic pumps. If an ultra low speed travel signal is issued in response to an ultra-low-speed switch turned on, one of the control valves is fixed to a neutral position by a solenoid valve. And a displacement amount of a travel motor is fixed at a maximum displacement by another solenoid valve. In this way, an upper limit for motor rotation speed is significantly reduced. As a result, it is possible to realize the ultra low speed travel with maximum operation of an accelerator pedal, without the need for subtle operation of the accelerator pedal.

Abstract: A brake release unit is provided between a transmission control unit for controlling a transmission and a clutch device. Pressure oil supplied from a hydraulic pressure source to the clutch device is also guided to an accumulator of the brake release unit. When the engine is stopped, pressure oil from the clutch device is collected in a reservoir, and the transmission operates as a parking brake. Pressure oil accumulated in the accumulator is kept as it is. If a solenoid switching valve of the brake release unit is driven as a result of operation of a switch in the operator's cabin, pressure oil accumulated in the accumulator is supplied to the clutch device. As a result, it is possible to easily release the parking brake.