Abstract: It is equipped with an injector body 4z which has formed therein high-pressure paths 6az, 6bz, and 6cz through which high-pressure fuel flows to a spray hole and stores therein a piezo-actuator 2z (i.e., an opening/closing mechanism) and a back-pressure control mechanism 3z (i.e., an opening/closing mechanism) which open or close the spray hole, a stem 51z (i.e., an elastic body) which is installed in said body 4z and elastically deformed when subjected to pressure of the high-pressure fluid, and a strain gauge 52z (i.e., a sensing device) which converts the degree of strain occurring at the stem 51z into an electric signal and outputs it as a measured-pressure signal. Specifically, the stain gauge 52z is installed on the stem 51z that is constructed as being separate from the body 4z.

Abstract: The injector body 4z which forms therein the high-pressure paths 6az, 6hz, and 6cz through which high-pressure fuel flows to a spray hole and has disposed therein the piezo-actuator 2z (drive means) to drive a needle (valve) to open or close the spray hole, the fuel pressure sensor 50z which is installed in the body 4z to measure the pressure of the high-pressure fuel, the sensor terminals 55z to output a measured pressure value from the fuel pressure sensor 50z externally, the drive terminals 56z to which the electric power for the piezo-actuator 2z is supplied, and the connector housing 70z retaining the sensor terminals 55z and the drive terminals 56z are provided. The sensor terminals 55z, the drive terminals 56z, and the connector housing 70z constitute a single connector.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is to be installed in a cylinder head of the engine and has a fuel pressure sensor working to measure the pressure of fuel within a injector body. The fuel pressure sensor is installed in a portion of the injector body which is to be located away from the cylinder head of the engine across a portion of the injector body on which a mechanical pressure is exerted by an external member such as a fuel supply pipe or a fuel drain pipe, thereby keeping the fuel pressure sensor free from internal stress, as arising from the mechanical pressure exerted on the injector body, to ensure the accuracy in measuring the pressure of the fuel.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is equipped with a fuel pressure sensor which is installed in a metallic injector body. The fuel injector also includes an amplifier working to amplify an output of the fuel pressure sensor and a thermal insulating member disposed between the metallic injector body and the amplifier to shield the amplifier thermally, thereby ensuring the accuracy in measuring the pressure of fuel within the fuel injector.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is equipped with a fuel pressure sensor, a sensor circuit such as an amplifier, and a valve actuator such as a piezoelectric actuator. The fuel injector also includes a conductive shield which is disposed between the sensor circuit and actuator drive terminals to supply electric power to the actuator and works to shield the sensor circuit from electric noises arising from the drive terminals, thereby minimizing the addition of the noises to an output of the fuel pressure sensor, as being processed in the sensor circuit, and ensuring the accuracy in determining the pressure of fuel based on the output of the fuel pressure sensor.

Abstract: A fuel injection device wherein when the combined natural resonant period of a piezo stack and a driving member constituting part of a piezo injector of a fuel injection device is denoted by T, and the voltage rise time taken from the moment the charging to the piezo stack is initiated until the piezo stack is charged to a target charge voltage is denoted by t, then, in order to prevent oscillating loads from being applied to the piezo stack after elapse of the voltage rise time t when t?0.5 T±0.1 T, the voltage rise time t that satisfies the relation 0.6T?t is set in a controller for the piezo injector and, thus, the voltage rise slope of the piezo stack immediately before reaching the end of the voltage rise time t is made gentler to suppress the expansion and contraction force occurring in the piezo stack and thereby enhance the long-term reliability of the piezo stack.

Abstract: An electromagnetic apparatus for driving a valve such as an intake valve of an internal combustion engine drives the valve to its closing position without generating vibration and noises which are detrimental to durability and reliability of the valve. The valve speed is controlled either mechanically or electrically so that it is reduced to substantially zero when the valve sits on a valve seat. To mechanically control the valve speed, air or magnetic liquid is used as a cushion against the valve movement, or springs having a non-linear spring modulus such as a double-spring or a barrel spring are used to bias the valve movement. To electrically control the valve speed, an electrical signal representing the valve position is used to determine energization timing of the solenoids which drive the valve to an open or closing position. Such electrical signal is generated by an eddy current, resistance or spring load detector.

Abstract: For regenerating an exhaust gas particulate collecting filter, there is provided an exhaust gas particulate purifying process in which damage to the filter caused by a thermal action can be prevented and further electric power can be saved when an electric current supply to an electric heater attached to the filter is controlled. In the filter container (4), an electric heater (21) is provided on an end surface of the filter on an upstream side with respect to a regenerating gas flow, or provided at a position close to the end surface. Also, a temperature sensor (22) for measuring a temperature of the filter is provided inside the filter or at a position close to an end surface of the filter opposite to the aforementioned end surface.