Exhaust gas purification system

Abstract

An exhaust gas purification system is provided with an exhaust gas purification device ( 19 ) for trapping particulate matter, and a control system that performs a regeneration control process to the exhaust gas purification device ( 19 ), wherein in cases where the regeneration control process is interrupted in accordance with stop of an internal combustion engine ( 10 ), during the stop of the internal combustion engine ( 10 ) (or at the time of starting thereof), the control system determines, based on a temperature (catalyst bed temperature) and an amount of PM deposition of the exhaust gas purification device ( 19 ), whether the exhaust gas purification device ( 19 ) is in a state where the regeneration control process can not be carried out efficiently, and does not resume the regeneration control process at the time of starting of the internal combustion engine ( 10 ), in cases where the exhaust gas purification device ( 19 ) is in the state where the regeneration control process can not be carried out efficiently.

1 . An exhaust gas purification system comprising:
 an exhaust gas purification device for trapping particulate matter in an exhaust gas of an internal combustion engine;   a determination unit that determines, based on status information including a temperature of said exhaust gas purification device and an amount of particulate matter remaining in said exhaust gas purification device, whether the state of said exhaust gas purification device is a regeneration unsuitable state where a regeneration control process, which raises the temperature of said exhaust gas purification device thereby to regenerate said exhaust gas purification device by adding fuel into the exhaust gas, can not be carried out in an efficient manner; and   a control unit that starts, when a prescribed condition is satisfied, the regeneration control process in which the temperature of said exhaust gas purification device is raised to regenerate said exhaust gas purification device by adding fuel into the exhaust gas, and interrupts the regeneration control process in cases where said internal combustion engine is stopped during the execution of the regeneration control process, wherein in cases where it is not determined by said determination unit that the state of said exhaust gas purification device is said regeneration unsuitable state at the time of starting of said internal combustion engine after the interruption of the regeneration control process, said control unit resumes the regeneration control process, and in cases where it is determined by said determination unit that the state of said exhaust gas purification device is said regeneration unsuitable state at the time of starting of said internal combustion engine after the interruption of the regeneration control process, said control unit thereafter starts the regeneration control process at the time when said prescribed condition is satisfied.   
     
     
         2 . An exhaust gas purification system comprising:
 an exhaust gas purification device for trapping particulate matter in an exhaust gas of an internal combustion engine;   a determination unit that determines, based on status information including a stop period of time of said internal combustion engine and an amount of particulate matter remaining in said exhaust gas purification device, whether the state of said exhaust gas purification device is a regeneration unsuitable state where a regeneration control process, which raises the temperature of said exhaust gas purification device thereby to regenerate said exhaust gas purification device by adding fuel into the exhaust gas, can not be carried out in an efficient manner; and   a control unit that starts, when a prescribed condition is satisfied, the regeneration control process in which the temperature of said exhaust gas purification device is raised to regenerate said exhaust gas purification device by adding fuel into the exhaust gas, and interrupts the regeneration control process in cases where said internal combustion engine is stopped during the execution of the regeneration control process, wherein in cases where it is not determined by said determination unit that the state of said exhaust gas purification device is said regeneration unsuitable state at the time of starting of said internal combustion engine after the interruption of the regeneration control process, said control unit resumes the regeneration control process, and in cases where it is determined by said determination unit that the state of said exhaust gas purification device is said regeneration unsuitable state at the time of starting of said internal combustion engine after the interruption of the regeneration control process, said control unit thereafter starts the regeneration control process at the time when said prescribed condition is satisfied.   
     
     
         3 . The exhaust gas purification system as set forth in  claim 1 , wherein
 said control unit is   a unit which manages, as the number of cancellations, the number of determinations continuously made that the regeneration control process should not be resumed, and at the same time,   a unit which resumes the regeneration control process when said frequency of cancellations is equal to or more than a predetermined number of cancellations, even in cases where it is determined by said determination unit that the state of said exhaust gas purification device is said regeneration unsuitable state.   
     
     
         4 . The exhaust gas purification system as set forth in  claim 1 , wherein
 said internal combustion engine is an internal combustion engine which is mounted on a vehicle and which is automatically stopped at the time when said vehicle is stopped.   
     
     
         5 . The exhaust gas purification system as set forth in  claim 2 , wherein
 said control unit is   a unit which manages, as the number of cancellations, the number of determinations continuously made that the regeneration control process should not be resumed, and at the same time,   a unit which resumes the regeneration control process when said frequency of cancellations is equal to or more than a predetermined number of cancellations, even in cases where it is determined by said determination unit that the state of said exhaust gas purification device is said regeneration unsuitable state.   
     
     
         6 . The exhaust gas purification system as set forth in  claim 2 , wherein
 said internal combustion engine is an internal combustion engine which is mounted on a vehicle and which is automatically stopped at the time when said vehicle is stopped.   
     
     
         7 . The exhaust gas purification system as set forth in  claim 3 , wherein
 said internal combustion engine is an internal combustion engine which is mounted on a vehicle and which is automatically stopped at the time when said vehicle is stopped.   
     
     
         8 . The exhaust gas purification system as set forth in  claim 5 , wherein
 said internal combustion engine is an internal combustion engine which is mounted on a vehicle and which is automatically stopped at the time when said vehicle is stopped.