US 2004/0103714 A1Published application

Knock detection device

AssigneeFujitsu Ten Limited

InventorsKoji Fukuoka, Kenji Kasashima, Yuji Miyanoo, Masashi Yoshimi

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Abstract

A knock detection device that can not only detect knock accurately, but can also detect heavy knock quickly. Cylinder pressure is detected by a pressure sensor installed in each cylinder in an internal combustion engine. AS the occurrence or non-occurrence of heavy knock is determined based on the ratio between the maximum value of cylinder pressure fluctuation and the maximum value of cylinder pressure divided by a prescribed value, it becomes possible to detect the occurrence of heavy knock quickly. If it is determined that heavy knock has occurred, a knock suppression measure involving, for example, reducing the spark advance angle, is immediately applied, thus preventing damage to the internal combustion engine.

Claims10

Dependent claims

A knock detection device comprising:

cylinder pressure detecting means for detecting cylinder pressure in an internal combustion engine;
threshold value computing means for computing a knock detection threshold value based on cylinder pressures for a plurality of cycles detected by said cylinder pressure detecting means;
and knock occurrence determining means for determining the occurrence or non-occurrence of knock, based on said threshold value computed by said threshold value computing means, wherein said knock detection device further comprises:
maximum cylinder pressure detecting means for detecting a maximum cylinder pressure in each cycle from said cylinder pressures detected by said cylinder pressure detecting means;
maximum cylinder pressure fluctuation detecting means for detecting a maximum cylinder pressure fluctuation in each cycle from said cylinder pressures detected by said cylinder pressure detecting means;
and
heavy knock occurrence determining means for determining the occurrence or non-occurrence of heavy knock in a given cycle, based on said maximum cylinder pressure fluctuation detected by said maximum cylinder pressure fluctuation detecting means and said maximum cylinder pressure detected by said maximum cylinder pressure detecting means.

4 more elements

A knock detection device comprising:

a cylinder pressure sensor for detecting cylinder pressure in an internal combustion engine;
a threshold value computing unit for computing a knock detection threshold value based on cylinder pressures for a plurality of cycles detected by said cylinder pressure sensor;
and a knock occurrence determining unit for determining the occurrence or non-occurrence of knock, based on said threshold value computed by said threshold value computing unit, wherein said knock detection device further comprises:
a maximum cylinder pressure detecting unit for detecting a maximum cylinder pressure in each cycle from said cylinder pressures detected by said cylinder pressure sensor;
a maximum cylinder pressure fluctuation detecting unit for detecting a maximum cylinder pressure fluctuation in each cycle from said cylinder pressures detected by said cylinder pressure sensor;
and
a heavy knock occurrence determining unit for determining the occurrence or non-occurrence of heavy knock in a given cycle, based on said maximum cylinder pressure fluctuation detected by said maximum cylinder pressure fluctuation detected unit and said maximum cylinder pressure detected by said maximum cylinder pressure detecting unit.

4 more elements

Dependencies are inferred from the claim text.