ENGINE - 2AZ-FE ENGINE
214CE04
: Conventional Type
: Flat Type
(V)
Vo l t a g e
Frequency (Hz)A
BA: Detection Band of
Conventional Type
B: Detection Band of
Flat Type
Characteristic of Knock Sensor
214CE01214CE02
Steel Weight
Insulator
Piezoelectric
ElementOpen / Short Circuit
Detection Resistor
Flat Type Knock Sensor
(Non-resonant Type)Piezoelectric
Element
Vibration Plate
Conventional Type Knock Sensor
(Resonant Type)EG-39
Knock Sensor (Flat Type)
1) General
In the conventional type knock sensor (resonant type), a vibration plate which has the same resonance
point as the knocking frequency of the engine is built in and can detect the vibration in this frequency
band.
On the other hand, a flat type knock sensor (non-resonant type) has the ability to detect vibration in a
wider frequency band from about 6 kHz to 15 kHz, and has the following features.
The engine knocking frequency will change a bit depending on the engine speed. The flat type knock
sensor can detect the vibration even when the engine knocking frequency is changed. Thus the
vibration detection ability is increased compared to the conventional type knock sensor, and a more
precise ignition timing control is possible.
2) Construction
The flat type knock sensor is installed on the engine through the stud bolt installed on the cylinder
block. For this reason, a hole for the stud bolt is running through the center of the sensor.
Inside of the sensor, a steel weight is located on the upper portion and a piezoelectric element is located
under the weight through the insulator.
The open / short circuit detection resistor is integrated.
