Non-resonance type knock sensor attachment state detection system, non-resonance type knock sensor attachment state detection apparatus, non-resonance type knock sensor attachment state detection method

摘要

PROBLEM TO BE SOLVED: To provide an attachment state detection system, an attachment state detection device and an attachment state detection method for a non-resonance type knock sensor that can appropriately detect the attachment state of the non-resonance type knock sensor without being dependent on vibration of an engine.SOLUTION: An attachment state detection system 1 comprises a non-resonance type knock sensor 10 attached to an engine ENG and having a first terminal 10a and a second terminal 10b each of which is connected to a piezoelectric element 11 stored therein; an input part 41 having a resistor 24 connected to the first terminal and an earth wiring 26 having the second terminal connected to the earth and applying an input signal Si with a frequency f higher than a knock detection frequency range RK of the sensor to the first terminal through the resistor 24; an output detection part 42 for detecting a magnitude Vro of a responding output signal Sro generated at the first terminal of the sensor in response to the input signal; and determination parts S416, S426, S434 for determining an attachment state of the sensor to the engine in reference to a frequency characteristic of the magnitude of a responding output signal at a determination frequency f3 higher than the knock detection frequency range or the magnitude of responding output signals at determination frequency ranges RF1, RF2.SELECTED DRAWING: Figure 6