Exhaust-gas processing device for a diesel engine

An exhaust-gas processing device for a diesel engine loaded on a machine, the device comprising a DPF (1), a DPF regenerator (3) arranged upstream of an inlet of the DPF and having an outlet configured to pass exhaust gas to the inlet of the DPF, a controller coupled to the DPF regenerator and configured to presume an amount of PM deposited on the DPF and to control the DPF regenerator, a memory (5) coupled to the controller, an indicator light (6) mounted to the machine and coupled to the controller, and which, when activated, sends a message signaling demand for accelerated regeneration, and a user-operated actuator (7) coupled to the controller and operable to start accelerated regeneration, wherein

• the memory (5) stores a plurality of judging values (J2), (J3) regarding an assumed value of the PM deposited amount and a term (T1) for reserving the judgment as to the demand for accelerated regeneration;
• the plurality of judging values (J2), (J3) comprises a value (J2) for judgment as to the demand for accelerated regeneration and a value (J3) for judgment as to starting the normal regeneration, higher than the judging value (J2);
• the controller compares the assumed value of the PM deposited amount with the plurality of judging values (J2), (J3);
• when the assumed value of the PM deposited amount has increased to the value (J3) for judgment as to starting the normal regeneration, the controller automatically enables the DPF regenerator (3) to start the normal regeneration processing (S2) so as to increase the temperature of the exhaust gas to be passed through the DPF (1);
• when the normal regeneration processing is being continued (S6) since it has started (S2), the time when the term (T1) for reserving the judgment as to the demand for the accelerated regeneration has elapsed is regarded as the judging time (T3) as to the demand for accelerated regeneration, at this time (T3) for judgment as to the demand for accelerated regeneration, in the event that the assumed value of the PM deposited amount exceeds the value (J2) for judgment as to the demand for accelerated regeneration, the accelerated regeneration being deemed to be demanded and the controller allowing the indicator light (6) to start (S8) sending the message to demand the accelerated regeneration;
• and
• when the accelerated-regeneration starting operation has been performed by the user-operated actuator (7), the controller enables the DPF regenerator (3) to switch the normal regeneration processing over to the accelerated regeneration processing (S10) to increase the temperature of the exhaust gas to be passed through the DPF (1) so as to accelerate the regeneration speed of the DPF (1) more than the case of the normal regeneration processing.