COMBUSTION PRESSURE SENSOR WITH BUILT-IN CHARGE AMPLIFIER

摘要

In a combustion pressure sensor having built-in charge amplifier, signal line overheating and deterioration of detection accuracy is restricted. The combustion pressure sensor includes a sensor body that includes a piezoelectric element having one end connected to chassis ground through a housing and detects pressure in a combustion chamber of engine, and a charge amplifier that includes at least a voltage converting unit converting output of the sensor body into voltage signal and a reference voltage generating unit generating reference voltage supplied to the voltage converting unit and operates on power supplied from a signal processing unit disposed outside. The reference voltage generating unit includes a voltage generating circuit having a constant current circuit and a resistor connected in series. The voltage generating circuit has one end connected to power line extending from the signal processing unit, and the other end connected to the end of the piezoelectric element.

主权项

1. A combustion pressure sensor with a built-in charge amplifier comprising:
a sensor body including a piezoelectric element having a ground side end connected to a chassis ground through a housing, and detecting a pressure in a combustion chamber of an engine; and a charge amplifier including at least a voltage converting unit that converts an output of the sensor body into a voltage signal and a reference voltage generating unit that generates a reference voltage for being supplied to the voltage converting unit, and operating on a power supplied from a signal processing unit disposed outside of the charge amplifier, wherein the reference voltage generating unit includes a voltage generating circuit having a constant current circuit and a resistor connected in series with each other, one end of the voltage generating circuit is connected to a power supply line extending from the signal processing unit, and the other end of the voltage generating circuit is connected to the ground side end of the piezoelectric element.