Preignition detection apparatus

• US 5,905,193 A
• Filed: 07/02/1997
• Issued: 05/18/1999
• Est. Priority Date: 07/15/1996
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hashizume, Katsushi, Mogi, Kazuhisa
• Primary Examiner(s): Dombroske, George
• Assistant Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US08/888,337
• Time in Patent Office: 685 Days
• Field of Search: 73/35.09, 73/35.11, 73/116, 73/117.3, 73/118.1, 123/425, 701/111
• US Class Current: 73/35.09
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: G01L 23/221 for detecting or indicating knocks in internal combustion engines
• CPC Class Codes: G01L 23/225 circuit arrangements therefor
• CPC Class Codes: G01M 15/12 by monitoring vibrations

Abstract

The invention provides a preignition detection device that is capable of detecting a preignition condition (PI) in an incipient stage. Engine vibration is detected by a vibration sensor 113 and read into a controller 12. When the length of a period during which abnormal vibration of a magnitude greater than a predetermined level occurs in succession has exceeded a predetermined length of period, or when the frequency of occurrence of abnormal vibration during a predetermined period is greater than a predetermined value and the cumulative sum of the frequencies of occurrence of abnormal vibration has exceeded a predetermined value, then it is determined that preignition has occurred. Here, a determination value, based on which the occurrence of preignition is determined, can be varied to prevent erroneous decisions and to improve responsiveness.

Claims

1. A preignition detecting apparatus comprising:

a vibration detecting means for detecting vibration of an internal combustion engine;

an abnormal vibration occurrence interval measuring means for measuring a time interval while abnormal vibration higher than a predetermined level is being detected by the vibration detecting means;

a frequent vibration continuing interval measuring means for measuring a time interval while the abnormal vibration occurrence interval measured by the abnormal vibration occurrence interval measuring means is shorter than a predetermined non-abnormal vibration continuing interval; and

a preignition determining means for determining that preignition has occurred when the frequent vibration continuing interval measured by the frequent vibration continuing interval measuring means becomes longer than a predetermined preignition determining interval.

2. A preignition detecting apparatus of claim 1, wherein the frequent vibration continuing interval measuring means uses a non-abnormal vibration continuing interval determined in accordance with a non-abnormal vibration interval while a non-abnormal vibration lower than the predetermined level is being detected by the vibration detecting means.

3. A preignition detecting apparatus of claim 1, wherein the frequent vibration continuing interval measuring means uses a non-abnormal vibration continuing interval which becomes longer as an engine speed becomes lower.

4. A preignition detecting apparatus of claim 1, wherein the preignition determining means uses a preignition determining interval determined in accordance with a frequent vibration continuing interval.

13. A preignition detecting apparatus of claim 1, wherein the frequent vibration continuing interval measuring means measures the frequent vibration continuing interval in which the abnormal vibration occurs repeatedly.

14. A preignition detecting apparatus of claim 1, wherein the frequent vibration continuing interval is measured within the predetermined non-abnormal vibration continuing interval.

5. A preignition detecting apparatus comprising:

a vibration detecting means for detecting vibration of an internal combustion engine;

an abnormal vibration frequency calculating means for calculating a frequency of occurrence of abnormal vibration, wherein abnormal vibration is determined to occur when the vibration detected by the vibration detecting means is higher than a predetermined level;

an accumulating means for accumulating the frequency calculated by the abnormal vibration frequency calculating means; and

a preignition determining means for determining that preignition has occurred when the accumulated frequency becomes larger than a predetermined preignition determining value.

6. A preignition detecting apparatus of claim 5, wherein the preignition determining means uses a preignition determining value which becomes larger as an engine speed becomes lower.

15. A preignition detecting apparatus of claim 5, wherein the abnormal vibration frequency calculating means calculates a frequency of repeated occurrences of the abnormal vibration.

16. A preignition detecting apparatus of claim 5, wherein the abnormal vibration frequency calculating means calculates the frequency within a predetermined non-abnormal vibration continuing interval.

7. A preignition detecting method comprising the steps of:

a vibration detecting step for detecting vibration of an internal combustion engine;

an abnormal vibration occurrence interval measuring step for measuring a time interval while abnormal vibration higher than a predetermined level is being detected at the vibration detecting step;

a frequent vibration continuing interval measuring step for measuring a time interval while the abnormal vibration occurrence interval measured at the abnormal vibration occurrence interval measuring step is shorter than a predetermined non-abnormal vibration continuing interval; and

a preignition determining step for determining that preignition has occurred when the frequent vibration continuing interval measured at the frequent vibration continuing interval measuring step becomes longer than a predetermined preignition determining interval.

8. A preignition detecting method of claim 7, wherein the frequent vibration continuing interval measuring step uses a non-abnormal vibration continuing interval determined in accordance with a non-abnormal vibration interval while a non-abnormal vibration lower than the predetermined level is being detected at the vibration detecting step.

9. A preignition detecting method of claim 7, wherein the frequent vibration continuing interval measuring step uses a non-abnormal vibration continuing interval which becomes longer as an engine speed becomes lower.

10. A preignition detecting method of claim 7, wherein the preignition determining step uses a preignition determining interval determined in accordance with a frequent vibration continuing interval.

17. A preignition detecting method of claim 7, wherein the frequent vibration continuing interval includes a time interval in which the abnormal vibration occurs repeatedly.

18. A preignition detecting method of claim 7, wherein the frequent vibration continuing interval is measured within the predetermined non-abnormal vibration continuing interval.

11. A preignition detecting method comprising the steps of:

a vibration detecting step for detecting vibration of an internal combustion engine;

an abnormal vibration frequency calculating step for calculating a frequency of occurrence of abnormal vibration, wherein abnormal vibration is determined to occur when the vibration detected at the vibration detecting step is higher than a predetermined level;

an accumulating step for accumulating the frequency calculated at the abnormal vibration frequency calculating step; and

a preignition determining step for determining that preignition has occurred when the accumulated frequency becomes larger than a predetermined preignition determining value.

12. A preignition detecting method of claim 11, wherein the preignition determining step uses a preignition determining value which becomes larger as an engine speed becomes lower.

19. A preignition detecting method of claim 11, wherein the abnormal vibration frequency calculating step includes a substep of calculating a frequency of repeated occurrences of the abnormal vibration.

20. A preignition detecting method of claim 11, wherein the frequency is calculated within a predetermined non-abnormal vibration continuing interval.