Motor vehicle and control method of motor vehicle

Abstract

In a hybrid vehicle of the invention, in the event of specification that an exhaust treatment catalyst is in a preset adequate state at step S 112 , combustion control of an engine starts after a decrease of an intake pipe pressure P to a preset reference negative pressure Pref and reduction of an intake air flow into a cylinder of the engine by engine motoring. In the event of specification that the exhaust treatment catalyst is not in the preset adequate state but in an inadequate state at step S 112 , on the other hand, the combustion control of the engine immediately starts, prior to the decrease of the intake pipe pressure P to the preset reference negative pressure Pref. The hybrid vehicle of the invention allows an early start of the combustion control in a lower catalyst temperature condition that lowers the catalytic conversion power of the exhaust treatment catalyst and in a higher catalyst temperature condition that causes accelerated deterioration of the exhaust treatment catalyst in exposure to the air. The early start of the combustion control effectively reduces the potential shocks on a start of the engine, while preventing the potential troubles, for example, the worsened emission and the accelerated deterioration of the exhaust treatment catalyst, arising in the course of engine motoring due to the inadequate state of the exhaust treatment catalyst.

1 . A motor vehicle, comprising: 
 a motoring device that is capable of motoring an internal combustion engine;    an exhaust treatment catalyst that treats exhaust of the internal combustion engine to convert harmful components of the exhaust into harmless components;    a catalyst state detection unit that detects a state of the exhaust treatment catalyst;    an in-cylinder air flow specification module that specifies whether an intake air flow into a cylinder of the internal combustion engine decreases to a preset low range; and    an internal combustion engine start control module that starts combustion control of the internal combustion engine, in response to requirement for a restart of the internal combustion engine,    when the state of the exhaust treatment catalyst detected by the catalyst state detection unit is a preset adequate state, said internal combustion engine start control module starting the combustion control of the internal combustion engine after specification of a decrease in intake air flow into the cylinder of the internal combustion engine to the preset low range by said in-cylinder air flow specification module in the course of motoring the internal combustion engine by the motoring device,    when the state of the exhaust treatment catalyst detected by the catalyst state detection unit is not the preset adequate state but is an inadequate state, said internal combustion engine start control module immediately starting the combustion control of the internal combustion engine, prior to specification of a decrease in intake air flow into the cylinder of the internal combustion engine to the preset low range by said in-cylinder air flow specification module in the course of motoring the internal combustion engine by the motoring device.    
   
   
       2 . A motor vehicle in accordance with  claim 1 , wherein the preset low range represents a certain level of the intake air flow into the cylinder that is equivalent to idling operation of the internal combustion engine.  
   
   
       3 . A motor vehicle in accordance with  claim 1 , said motor vehicle further comprising: 
 an intake pipe pressure specification module that specifies whether an intake pipe pressure of the internal combustion engine decreases to a preset reference negative pressure,    wherein said in-cylinder air flow specification module specifies whether the intake air flow into the cylinder of the internal combustion engine decreases to the preset low range, based on a result of the specification of whether the intake pipe pressure of the internal combustion engine decreases to the preset reference negative pressure.    
   
   
       4 . A motor vehicle in accordance with  claim 3 , wherein the preset reference negative pressure represents a certain level of the intake pipe pressure that is equivalent to idling operation of the internal combustion engine.  
   
   
       5 . A motor vehicle in accordance with  claim 3 , wherein said intake pipe pressure specification module specifies whether the intake pipe pressure of the internal combustion engine decreases to the preset reference negative pressure, based on a specific parameter in correlation to the intake pipe pressure of the internal combustion engine.  
   
   
       6 . A motor vehicle in accordance with  claim 5 , wherein the specific parameter is a motoring time of the internal combustion engine by the motoring device.  
   
   
       7 . A motor vehicle in accordance with  claim 1 , wherein the catalyst state detection unit detects the inadequate state of the exhaust treatment catalyst, when the exhaust treatment catalyst has a temperature in a low temperature range that allows exertion of only an insufficient catalytic conversion power.  
   
   
       8 . A motor vehicle in accordance with  claim 1 , wherein the catalyst state detection unit detects the inadequate state of the exhaust treatment catalyst, when the exhaust treatment catalyst has a temperature in a high temperature range that causes quick deterioration of the exhaust treatment catalyst by exposure to the air.  
   
   
       9 . A motor vehicle in accordance with  claim 1 , said motor vehicle further comprising an internal combustion engine stop control module that stops the operation of the internal combustion engine upon satisfaction of a preset internal combustion engine auto stop condition, 
 wherein said internal combustion engine start control module restarts the internal combustion engine upon satisfaction of a preset internal combustion engine auto start condition after the stop of the operation of the internal combustion engine by said internal combustion engine stop control module.    
   
   
       10 . A motor vehicle in accordance with  claim 9 , wherein said internal combustion engine stop control module prohibits the stop of the internal combustion engine when the exhaust treatment catalyst is not in the preset adequate state during operation of the internal combustion engine.  
   
   
       11 . A motor vehicle, comprising: 
 a motoring device that is capable of motoring an internal combustion engine;    an exhaust treatment catalyst that treats exhaust of the internal combustion engine to convert harmful components of the exhaust into harmless components;    a catalyst state detection unit that detects a state of the exhaust treatment catalyst;    an intake pipe pressure specification module that specifies whether an intake pipe pressure of the internal combustion engine decreases to a preset reference negative pressure; and    an internal combustion engine start control module that starts combustion control of the internal combustion engine, in response to requirement for a restart of the internal combustion engine,    when the state of the exhaust treatment catalyst detected by the catalyst state detection unit is a preset adequate state, said internal combustion engine start control module starting the combustion control of the internal combustion engine after specification of a decrease in intake pipe pressure of the internal combustion engine to the preset reference negative pressure by said intake pipe pressure specification module in the course of motoring the internal combustion engine by the motoring device,    when the state of the exhaust treatment catalyst detected by the catalyst state detection unit is not the preset adequate state but is an inadequate state, said internal combustion engine start control module immediately starting the combustion control of the internal combustion engine, prior to specification of a decrease in intake pipe pressure of the internal combustion engine to the preset reference negative pressure by said intake pipe pressure specification module in the course of motoring the internal combustion engine by the motoring device.    
   
   
       12 . A motor vehicle in accordance with  claim 11 , wherein the preset reference negative pressure represents a certain level of the intake pipe pressure that is equivalent to idling operation of the internal combustion engine.  
   
   
       13 . A motor vehicle in accordance with  claim 11 , wherein said intake pipe pressure specification module specifies whether the intake pipe pressure of the internal combustion engine decreases to the preset reference negative pressure, based on a specific parameter in correlation to the intake pipe pressure of the internal combustion engine.  
   
   
       14 . A motor vehicle in accordance with  claim 13 , wherein the specific parameter is a motoring time of the internal combustion engine by the motoring device.  
   
   
       15 . A motor vehicle in accordance with  claim 11 , wherein the catalyst state detection unit detects the inadequate state of the exhaust treatment catalyst, when the exhaust treatment catalyst has a temperature in a low temperature range that allows exertion of only an insufficient catalytic conversion power.  
   
   
       16 . A motor vehicle in accordance with  claim 11 , wherein the catalyst state detection unit detects the inadequate state of the exhaust treatment catalyst, when the exhaust treatment catalyst has a temperature in a high temperature range that causes quick deterioration of the exhaust treatment catalyst by exposure to the air.  
   
   
       17 . A motor vehicle in accordance with  claim 11 , said motor vehicle further comprising an internal combustion engine stop control module that stops the operation of the internal combustion engine upon satisfaction of a preset internal combustion engine auto stop condition, 
 wherein said internal combustion engine start control module restarts the internal combustion engine upon satisfaction of a preset internal combustion engine auto start condition after the stop of the operation of the internal combustion engine by said internal combustion engine stop control module.    
   
   
       18 . A motor vehicle in accordance with  claim 17 , wherein said internal combustion engine stop control module prohibits the stop of the internal combustion engine when the exhaust treatment catalyst is not in the preset adequate state during operation of the internal combustion engine.  
   
   
       19 . A control method of a motor vehicle, comprising the steps of: 
 (a) detecting a state of an exhaust treatment catalyst that treats exhaust of the internal combustion engine to convert harmful components of the exhaust into harmless components; and    (b) when the state of the exhaust treatment catalyst detected by the step (a) is a preset adequate state, starting the combustion control of the internal combustion engine after specification of a decrease in intake air flow into the cylinder of the internal combustion engine to the preset low range, in the course of motoring the internal combustion engine,    and when the state of the exhaust treatment catalyst detected by the step (a) is not the preset adequate state but is an inadequate state, starting the combustion control of the internal combustion engine, prior to specification of a decrease in intake air flow into the cylinder of the internal combustion engine to the preset low range in the course of motoring the internal combustion engine.    
   
   
       20 . A control method of a motor vehicle, comprising the steps of: 
 (a) detecting a state of an exhaust treatment catalyst that treats exhaust of the internal combustion engine to convert harmful components of the exhaust into harmless components; and    (b) when the state of the exhaust treatment catalyst detected by the step (a) is a preset adequate state, starting the combustion control of the internal combustion engine after specification of a decrease in intake pipe pressure of the internal combustion engine to the preset reference negative pressure in the course of motoring the internal combustion engine,    and when the state of the exhaust treatment catalyst detected by the step (a) is not the preset adequate state but is an inadequate state, starting the combustion control of the internal combustion engine, prior to specification of a decrease in intake pipe pressure of the internal combustion engine to the preset reference negative pressure in the course of motoring the internal combustion engine.