Exhaust gas purification device for vehicle

Abstract

Provided is an exhaust gas purification device for a vehicle, wherein even in a vehicle in which the operation and stop of an internal combustion engine are frequently repeated, exhaust gas is prevented from being discharged to the outside of the vehicle while being insufficiently purified, and excessive decline in battery performance is prevented. Specifically provided is an exhaust gas purification device for a vehicle, the device being provided with a purge control means for executing purge processing for recovering a reducing agent remaining in a reducing agent supply unit after an internal combustion engine is stopped, wherein the purge control means executes the purge processing when it is determined at time of the stop of the internal combustion engine that the internal combustion engine is not restarted for a predetermined period of time or more and / or when it is determined that the stop of the internal combustion engine is not caused by control for automatically stopping the internal combustion engine when a predetermined idling stop condition is satisfied.

Description

technical field [0001] The present invention relates to an exhaust purification device mounted on a vehicle, which arranges a reduction catalyst in an exhaust passage of an internal combustion engine, and introduces a reducing agent supplied from a reducing agent supply part to the reduction catalyst together with exhaust gas, thereby Purify the exhaust gas. In particular, it relates to an exhaust purification device for purging reducing agent remaining in a reducing agent supply part when an internal combustion engine is stopped. Background technique [0002] Conventionally, as an exhaust purification device for purifying nitrogen oxides in the exhaust gas of a vehicle, there are many known exhaust purification devices configured to arrange a reduction catalyst such as a selective reduction catalyst in the exhaust passage. The catalyst supplies a reducing agent such as an aqueous urea solution stored in the reducing agent tank through the reducing agent supply unit into th...

AI Technical Summary

Problems solved by technology

On the other hand, at the time of restarting, if the reducing agent supply part is reliably returned to a state where the reducing agent can be supplied and then the internal combustion engine is started, it will take time until it becomes a state where it can run, which is not practical.

[0009] In addition, when the cleaning process is performed while the internal combustion engine is stopped, the power stored in the battery is consumed.

Especially in cold places, a heater is sometimes used to defrost the reducing agent or prevent the reducing agent from freezing when the internal combustion engine is started, and the power consumption increases significantly.

However, in a business vehicle or a vehicle capable of idling stop control, the running distance and running time are short each time the internal combustion engine is started and stopped, so the amount of electric power stored in the battery tends to be small while running.

Therefore, if the cleaning process is performed frequently, the battery power is likely to be insufficient.

In addition, in a business vehicle that repeatedly starts and stops the internal combustion engine or a vehicle that can perform idling stop control, if the cleaning process is performed every time the internal combustion engine is stopped, the frequency of use of the battery will increase, so the battery will deteriorate rapidly.

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