| 摘要 |
An engine (1) is equipped with a tank (210) that stores urea water, a level sensor (250) that detects the amount of urea water remaining in the tank (210), and a urea injection valve (230) that injects urea water in the tank (210) into an exhaust passage (26). A control device (80) determines whether misdetection is made in the level sensor (250) on the basis of a first urea remaining amount detected by the level sensor (250) immediately after the engine has stopped, and an integrated value for the urea water supply amount, and a second urea remaining amount detected by the level sensor (250) after the supplying of urea water has begun. When the control device (80) determines that misdetection is made in the level sensor (250), the control device sets, as the estimated value for the amount of urea in the tank (210), the value obtained by subtracting the integrated value for the urea water supply amount from the first urea remaining amount. |
