Abstract: A pressure detection device includes: a piezoelectric element that detects a pressure change via a diaphragm head or the like; a circuit board that is provided with a processing circuit that performs electrical processing with respect to a charge signal outputted from the piezoelectric element; a conductive housing member, which has conductivity and is disposed to cover (house) the circuit board, and which is connected to the ground of the circuit board; and a housing (a leading end side housing, the diaphragm head and a rear end side housing), which houses the piezoelectric element, the circuit board and the housing member, and which is electrically insulated from the piezoelectric element, the circuit board and the housing member.

Abstract: A pressure detecting device that detects the combustion pressure in an internal combustion engine includes: a piezoelectric element that outputs a charge signal corresponding to the pressure in a combustion chamber; and a mounting board on which are mounted an integrating circuit that integrates the charge signal outputted by the piezoelectric element and an amplifier circuit that amplifies a voltage signal obtained by integration. On the mounting board are provided: a power receiving terminal that receives a power-supply voltage from a controller; an output terminal that outputs an output signal after amplification to the controller; and a grounding terminal for making the ground of the controller and the mounting board common. Furthermore, in the mounting board, the grounding terminal and grounding ends of the integrating circuit and the amplifier circuit are connected by way of grounding ferrite beads.

Abstract: A disconnection detection circuit includes: a pull-up resistor to which the detection signal is fed and which connects a signal line connected to the wiring cable to a power supply or a pull-down resistor which connects the signal line to a GND; and a voltage clip circuit 105 which includes a high-voltage clip circuit which is connected between the signal line and the power supply and which clips the voltage of the signal line to the maximum specified voltage and a low-voltage clip circuit which is connected between the signal line and the GND and which clips the voltage of the signal line to the minimum specified voltage.

Abstract: A pressure detecting device that detects the combustion pressure in an internal combustion engine includes: a piezoelectric element that outputs a charge signal corresponding to the pressure in a combustion chamber; and a mounting board on which are mounted an integrating circuit that integrates the charge signal outputted by the piezoelectric element and an amplifier circuit that amplifies a voltage signal obtained by integration. On the mounting board are provided: a power receiving terminal that receives a power-supply voltage from a controller; an output terminal that outputs an output signal after amplification to the controller; and a grounding terminal for making the ground of the controller and the mounting board common. Furthermore, in the mounting board, the grounding terminal and grounding ends of the integrating circuit and the amplifier circuit are connected by way of grounding ferrite beads.

Abstract: An in-cylinder pressure detecting apparatus for detecting a pressure in a combustion chamber of an internal combustion engine is provided. The in-cylinder pressure detecting apparatus comprises a pressure detecting element mounted on a tip-portion of a fuel injection device which injects fuel into the combustion chamber, and an amplifying circuit unit having an amplifying circuit which amplifies a signal output from the pressure detecting element and outputs a pressure detection signal. An in-cylinder pressure detecting unit integrated fuel injection device is configured by integrating an in-cylinder pressure detecting unit with the fuel injection device. The in-cylinder pressure detecting unit includes the pressure detecting element, the amplifying circuit unit, and a connecting member connecting the pressure detecting element with the amplifying circuit unit. The in-cylinder pressure detecting unit integrated fuel injection device is mounted on the internal combustion engine.

Abstract: A pressure detection device includes: a piezoelectric element that detects a pressure change via a diaphragm head or the like; a circuit board that is provided with a processing circuit that performs electrical processing with respect to a charge signal outputted from the piezoelectric element; a conductive housing member, which has conductivity and is disposed to cover (house) the circuit board, and which is connected to the ground of the circuit board; and a housing (a leading end side housing, the diaphragm head and a rear end side housing), which houses the piezoelectric element, the circuit board and the housing member, and which is electrically insulated from the piezoelectric element, the circuit board and the housing member.

Abstract: A disconnection detection circuit includes: a pull-up resistor to which the detection signal is fed and which connects a signal line connected to the wiring cable to a power supply or a pull-down resistor which connects the signal line to a GND; and a voltage clip circuit 105 which includes a high-voltage clip circuit which is connected between the signal line and the power supply and which clips the voltage of the signal line to the maximum specified voltage and a low-voltage clip circuit which is connected between the signal line and the GND and which clips the voltage of the signal line to the minimum specified voltage.

Abstract: An in-cylinder pressure detecting apparatus for detecting a pressure in a combustion chamber of an internal combustion engine is provided. The in-cylinder pressure detecting apparatus includes a pressure detecting element mounted on a fuel injection device which injects fuel into the combustion chamber; and an amplifying circuit unit having an amplifying circuit which amplifies a signal output from the pressure detecting element and outputs a pressure detection signal. An in-cylinder pressure detecting unit including the pressure detecting element, the amplifying circuit unit, and a connecting member connecting the pressure detecting element with the amplifying circuit unit, is integrated with the fuel injection device, and an external surface of the amplifying circuit unit is shielded with metal thin film.

Abstract: An in-cylinder pressure detecting apparatus for detecting a pressure in a combustion chamber of an internal combustion engine is provided. The in-cylinder pressure detecting apparatus comprises a pressure detecting element mounted on a tip-portion of a fuel injection device which injects fuel into the combustion chamber, and an amplifying circuit unit having an amplifying circuit which amplifies a signal output from the pressure detecting element and outputs a pressure detection signal. An in-cylinder pressure detecting unit integrated fuel injection device is configured by integrating an in-cylinder pressure detecting unit with the fuel injection device. The in-cylinder pressure detecting unit includes the pressure detecting element, the amplifying circuit unit, and a connecting member connecting the pressure detecting element with the amplifying circuit unit. The in-cylinder pressure detecting unit integrated fuel injection device is mounted on the internal combustion engine.