Construction machine
A construction machine is capable of returning the posture of an earth removal plate (blade) from a rocking posture to a predetermined normal posture. A stay is mounted on the construction machine body to move in upward and downward directions. The earth removal plate is mounted on the distal end portion of the stay, and is rockably movable in forward and rearward directions by an angle cylinder controlled by a flow of hydraulic fluid in response to receiving an instruction about rocking the earth removal plate. A normalization switch gives an instruction to set the posture of the earth removal plate to a predetermined normal posture from the rocking posture. The posture of the earth removal plate is set to the predetermined normal posture from the rocking posture in response to the instruction from the normalization switch.
1 . A construction machine comprising: a stay mounted, on a machine body, turnably in upward and downward directions; an earth removal plate mounted, on a distal end portion of the stay, rockably in forward and rearward directions; an angle cylinder for rocking the earth removal plate in forward and rearward directions; a control valve for controlling a flow of hydraulic fluid flowing from a hydraulic pump to the angle cylinder; an operation unit for giving an instruction about rocking action of the earth removal plate in forward and rearward directions; and a controller for controlling the control valve in response to the instruction from the operation unit, wherein
the construction machine includes a normalization switch for giving an instruction to the controller to set a posture of the earth removal plate to a predetermined normal posture from a rocking posture for rocking the earth removal plate in forward and rearward directions, a pressure sensor for sensing a load pressure on the angle cylinder, and a buzzer,
the controller is configured to:
compute a stroke of the angle cylinder and store the computed stroke on a basis of an instruction signal from the operation unit;
control the control valve to set a stroke of the angle cylinder to a preset normal stroke in response to the instruction from the normalization switch; and
stop controlling the control valve and energize the buzzer when the load pressure sensed by the pressure sensor is higher than a predetermined threshold value in controlling the control valve in response to the instruction from the normalization switch.
2 . The construction machine according to claim 1 , wherein
the operation unit includes a pushbutton-type first operation switch for giving instruction about rocking one side of the earth removal plate when pressed shortly, and a pushbutton-type second operation switch for giving instruction about rocking another side of the earth removal plate when pressed shortly, and
at least one of the first operation switch and the second operation switch doubles as the normalization switch for setting the posture of the earth removal plate, from the rocking posture, to the predetermined normal posture when pressed long.