Patent ID: 11933023
Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Field: Civil engineering (Other fields)
Classification: CPC E  F  H  Y | IPC E  F  H

Claim 2:
3. A construction machine comprising:
an electrical equipment installed in a vehicle body;
a urea SCR controller installed in the vehicle body; and
a battery configured to supply power to the electrical equipment and the urea SCR controller, characterized in that:
the construction machine further comprises:
a plus-side main connection line configured to connect the electrical equipment and a plus terminal of the battery;
a plus-side isolating switch provided on the plus-side main connection line configured to connect or disconnect the electrical equipment to or from the plus terminal of the battery;
a key switch positioned at a downstream side of the plus-side isolating switch and is connected in series to the plus-side isolating switch, configured to connect or disconnect the electrical equipment to or from the plus terminal of the battery;
a plus-side auxiliary connection line positioned at an upstream side of the plus-side isolating switch configured to connect the urea SCR controller and the plus terminal of the battery;
a minus-side main connection line configured to connect a minus terminal of the battery to ground; and
a minus-side isolating switch provided on the minus-side main connection line configured to connect or disconnect the minus terminal of the battery to or from ground,
wherein the urea SCR controller is provided with a self-holding circuit,
the urea SCR controller puts the self-holding circuit into a connected state and executes control to return urea water to a tank when the key switch is turned off, and
after the key switch is turned off, the urea SCR controller puts the self-holding circuit into a cut-off state when the control to return urea water to the tank is completed.