Reducing agent supply device, method for controlling reducing agent supply device, and control device

A method for controlling a reducing agent supply device including a tank configured to store a reducing agent to be supplied into an exhaust pipe of an engine, pressure-feeding means configured to pressure-feed the reducing agent in the tank, a reducing agent supply channel through which the pressure-fed reducing agent is supplied, an injection nozzle configured to inject, into the exhaust pipe, the reducing agent supplied through the reducing agent supply channel, retraction means which includes a pump and configured to retract the reducing agent in the reducing agent supply channel back to a tank side using the pump, and a control device configured to control operation of the pressure-feeding means, the injection nozzle, and the retraction means, the method comprising:

• a step of causing the injection nozzle to repeat a switching operation in a predetermined cycle until the pump of the retraction means is stopped.

A control device in a reducing agent supply device including a tank configured to store a reducing agent to be supplied into an exhaust pipe of an engine, pressure-feeding means configured to pressure-feed the reducing agent in the tank, a reducing agent supply channel through which the pressure-fed reducing agent is supplied, an injection nozzle configured to inject, into the exhaust pipe, the reducing agent supplied through the reducing agent supply channel, and retraction means which includes a pump and configured to retract the reducing agent in the reducing agent supply channel back to a tank side using the pump, the control device controlling operation of the pressure-feeding means, the injection nozzle, and the retraction means and causing the injection nozzle to repeat a switching operation in a predetermined cycle until the pump of the retraction means is stopped.