Exhaust purifying apparatus of an internal combustion engine

Abstract

An exhaust purifying apparatus has an adsorbent capable of adsorbing hydrocarbons in an exhaust passage of an internal combustion engine, estimates the temperature of the adsorbent by repeated processing to estimate the current value by adding an added value to the previous estimated value, and changes the added value in response to the intake air amount and the ignition timing of the internal combustion engine.

1 . An exhaust purifying apparatus of an internal combustion engine comprising:
 an adsorbent that adsorbs a hydrocarbon in an exhaust passage of the internal combustion engine;   a temperature estimation part that estimates a temperature of the adsorbent by repeating processing wherein an added value is added to the previous estimated value to obtain the current estimated value; and   an added value calculation part that calculates the added value to change the added value based on an intake air amount and an ignition timing of the internal combustion engine.   
   
   
       2 . The exhaust purifying apparatus of the internal combustion engine according to  claim 1 , further comprising:
 a valve mechanism, provided in the exhaust passage, that changes an opening amount to change the passage condition of exhaust toward the adsorbent, wherein   the added value calculation part calculates the added value to change the added value based on the opening amount of the valve mechanism.   
   
   
       3 . The exhaust purifying apparatus of the internal combustion engine according to  claim 2 , wherein
 the exhaust passage has a multiple structure partitioned into a first passage disposed in the central part and a second passage disposed to surround an outer periphery of the first passage and to provide the adsorbent, and wherein   the valve mechanism provided upstream from the multiple structure is structured to limit exhaust flowing into the first passage, and is structured to change an opening amount between a fully closed position that allows exhaust to flow into the second passage and a fully open position that allows exhaust to flow into both the first passage and the second passage.   
   
   
       4 . The exhaust purifying apparatus of the internal combustion engine according to  claim 3 , further comprising:
 a driving apparatus that drives the valve mechanism to change the opening amount of the valve mechanism, wherein   the valve mechanism maintains an arbitrary opening amount between the fully closed position and the fully open position.   
   
   
       5 . The exhaust purifying apparatus of the internal combustion engine according to  claim 2 , wherein
 the added value calculation part calculates the added value using a weighting coefficient based on the opening amount of the valve mechanism.   
   
   
       6 . The exhaust purifying apparatus of the internal combustion engine according to  claim 4 , wherein
 the added value calculation part calculates the added value using a weighting coefficient based on the opening amount of the valve mechanism.   
   
   
       7 . The exhaust purifying apparatus of the internal combustion engine according to  claim 1 , wherein
 the internal combustion engine is provided in a prescribed vehicle as one of a plurality of driving power sources for running, and the vehicle is configured to be runnable with only a driving power source for running other than the internal combustion engine, and wherein   the temperature estimation part estimates the temperature of the adsorbent when the internal combustion engine is in the stopped condition by successive subtraction of the subtracted value from the estimated temperature at the time the drive of internal combustion engine is stopped, and includes a subtracted value calculation part wherein the subtracted value is calculated considering a running condition of the vehicle when the internal combustion engine is in the stopped condition.   
   
   
       8 . The exhaust purifying apparatus of the internal combustion engine according to  claim 1 , further comprising:
 a time-keeping apparatus that measures a stopped time up to a subsequent start time of the internal combustion engine as the starting point of the time during which the drive of the internal combustion engine is stopped; and   a starting time temperature estimation part that estimates the temperature of the adsorbent at the starting time of the internal combustion engine based on the measured by the time-keeping apparatus, wherein   the temperature estimation part uses the estimation result from the starting time temperature estimation part as an initial value before adding the added valued.   
   
   
       9 . The exhaust purifying apparatus of the internal combustion engine according to  claim 1 , wherein
 the temperature estimation part, in the case in which the temperature of the estimation result by the starting time temperature estimation part is lower than that of an intake air, the temperature of the intake air instead of the estimation result is used as the initial value.   
   
   
       10 . A method of controlling of an exhaust purifying apparatus for an internal combustion engine comprising:
 calculating an initial value as a temperature estimation base of an adsorbent that adsorbs a hydrocarbon in an exhaust passage of the internal combustion engine;   acquiring an amount of intake air taken into the internal combustion engine;   acquiring an ignition timing of the internal combustion engine;   calculating an added value based on the intake air amount and the ignition timing;   estimating the temperature of an adsorbent by adding the added value to the initial value; and   controlling an exhaust purifying apparatus based on the estimated temperature of the adsorbent.