State determining apparatus for exhaust gas purifier

• US 6,758,033 B2
• Filed: 09/05/2002
• Issued: 07/06/2004
• Est. Priority Date: 09/07/2001
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Iwaki, Yoshihisa, Sato, Masahiro, Ueno, Masaki, Endo, Tetsuo, Takakura, Shiro
• Primary Examiner(s): Tran, Binh
• Application Number:
  US10/234,710
• Publication Number:
  US 20030056496A1
• Time in Patent Office: 670 Days
• Field of Search: 602/74, 602/76, 602/77, 602/78, 602/88, 602/92, 602/95, 602/97, 602/99, 602/85, 603/00
• US Class Current: 60/277
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 11/005 the temperature or pressure being estimated, e.g. by means of a theoretical model
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/0093 the purifying devices are of the same type
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2550/03 of sorbing activity of adsorbents or absorbents
• CPC Class Codes: F01N 3/0835 Hydrocarbons
• CPC Class Codes: F01N 3/0878 Bypassing absorbents or adsorbents
• CPC Class Codes: F01N 3/101 Three-way catalysts
• CPC Class Codes: F02D 2200/0418 Air humidity
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/027 to purge or regenerate the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/1456 with sensor output signal being linear or quasi-linear with the concentration of oxygen
• CPC Class Codes: F02D 41/1495 Detection of abnormalities in the air/fuel ratio feedback system
• CPC Class Codes: F02M 26/15 in relation to engine exhaust purifying apparatus
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A state determining apparatus for an exhaust gas purifier is provided for determining the state of the exhaust gas purifier including an adsorbent for adsorbing hydrocarbons; in accordance with the temperature state in the exhaust system of an internal combustion engine. The state determining apparatus is arranged in an exhaust system of the internal combustion engine. The state determining apparatus comprises a humidity sensor for detecting the humidity within a bypass exhaust pipe, and an ECU for determining the temperature state of the exhaust system and determining the state of adsorbent in accordance with the humidity within the bypass exhaust pipe detected by the humidity sensor and the temperature state in the exhaust system detected by the ECU.

Claims

1. A state determining apparatus for an exhaust gas purifier arranged in an exhaust system of an internal combustion engine for determining a state of said exhaust gas purifier including an adsorbent capable of adsorbing hydrocarbons and moisture in exhaust gases, said state determining apparatus comprising:

a humidity sensor arranged near said adsorbent in said exhaust system for detecting a humidity in an exhaust pipe of said exhaust system;

temperature state detecting means for detecting a temperature state in said exhaust system; and

adsorbent state determining means for determining a state of said adsorbent in accordance with the humidity in the exhaust pipe detected by said humidity sensor and the temperature state in said exhaust system detected by said temperature state detecting means.

2. A state determining apparatus for an exhaust gas purifier according to claim 1, further comprising:

calory calculating means for calculating calory supplied from said internal combustion engine to said exhaust system after said internal combustion engine is started,

wherein said adsorbent state determining means further determines the state of said adsorbent further in accordance with the calory calculated by said calory calculating means.

3. A state determining apparatus for an exhaust gas purifier according to claim 2, further comprising:

threshold determining means for determining a threshold based on the temperature state in said exhaust system detected at the time said internal combustion engine is started,

wherein said calory calculating means includes accumulated fuel injection amount calculating means for calculating an accumulated fuel amount supplied to said internal combustion engine from a start thereof as said calory, and

said adsorbent state determining means determines the state of said adsorbent based on a result of comparison between the accumulated fuel amount from the start of said internal combustion engine and the threshold when a changing amount of the value detected by said humidity sensor after said internal combustion engine is started exceeds a predetermined value set therefor.

4. A state determining apparatus for an exhaust gas purifier according to claim 1, further comprising:

ambient temperature detecting means for detecting an ambient temperature around said humidity sensor; and

relative humidity calculating means for calculating a relative humidity of exhaust gases from an output of said humidity sensor in accordance with the detected ambient temperature.

5. A state determining apparatus for an exhaust gas purifier according to claim 1, wherein said humidity sensor is arranged at a location downstream of said adsorbent in said exhaust system.

6. A state determining apparatus for an exhaust gas purifier according to claim 1, wherein said adsorbent state determining means determines the state of said adsorbent after a stop of said internal combustion engine.

7. A state determining apparatus for an exhaust gas purifier according to claim 6, wherein said adsorbent state determining means determines the state of said adsorbent within a predetermined period after said internal combustion engine is stopped.

8. A state determining apparatus for an exhaust gas purifier according to claim 6, wherein said humidity sensor is arranged at a location upstream of said adsorbent in said exhaust system.

9. A state determining apparatus for an exhaust gas purifier according to claim 6, further comprising:

operating condition detecting means for detecting whether or not said internal combustion engine is operated in a predetermined operating condition before said internal combustion engine is stopped,

wherein said adsorbent state determining means determines the state of said adsorbent when said operating condition detecting means detects that said internal combustion engine is operated in said predetermined operating condition before said internal combustion engine is stopped.

10. A state determining apparatus for an exhaust gas purifier according to claim 9, wherein said predetermined operating condition of said internal combustion engine is a condition in which an air/fuel mixture supplied to said internal combustion engine is at an air/fuel ratio near the stoichiometric air/fuel ratio during the operation of said internal combustion engine.

11. A state determining apparatus for an exhaust gas purifier according to claim 1, wherein said temperature state of said exhaust system is a temperature of a cooling water upon start of said internal combustion engine.

12. A state determining apparatus for an exhaust gas purifier according to claim 1, wherein said adsorbent state determining means includes adsorbent deterioration determining means for determining a deterioration of said adsorbent as the state of said adsorbent.

13. A state determining apparatus for an exhaust gas purifier according to claim 1, wherein said adsorbent comprises zeolite.