KNOCK DETECTOR

• Main Authors: IWATA, TOSHIO, YAMATA, TOSHIHARU, UETA, ATSUSHI
• Format: Patent
• Language: English; Korean
• Published: 23.05.1994
• Edition: 5
• Subjects: MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; TESTING

A knock sensor detects the vibration of an internal combustion engine and the half wave of its output of the sensor is amplified by a half wave amplifier. From the amplified output, a vibration-signal producing circuit produces a vibration signal representative of the vibration of engine in synchronism with the crank angle. An arithmetic operation unit produces a reference signal. Then a comparator compares the reference signal with the vibration signal to output a knock signal indicative of the occurrence of knocking of the engine when the vibration signal exceeds the reference signal. A gain adjusting circuit may be provided between the knock sensor and the half wave amplifier for adjusting the input level to the half wave amplifier to set the output level of the amplifier to a proper level. The half wave amplifier may be provided with a gain selecting circuit which automatically changes the gain of half wave amplifier in accordance with the level of the knock sensor output. The gain selecting circuit increases the gain when the sensor output is lower than a predetermined level and decreases when the sensor output is higher than a predetermined level. An inverse transformation circuit may be provided after the half wave amplifier having the gain selecting circuit, so that the level of vibration signal is compressed when the gain of half wave amplifier is increased, and the level is expanded when the gain is decreased so as to reproduce a vibration signal proportional to the knock sensor output,