Abstract: A knocking sensor comprises a casing for receiving a pickup assembly including a transducer, which produces an electrical signal in accordance with engine vibrations, and a connector having at least a single pin electrically connected to the transducer. The casing comprises a threaded projection to be screwed in a screw hole of an engine, and a nut-like periphery to be rotated by a tool. The knocking sensor can be attached to the engine by means of an impact wrench, by rotating the nut-like portion. A plug connected to one end of a shielding code can be plugged in the connector to make an electrical connection between the transducer and a signal processing circuit after the knocking sensor has been attached to the engine, and therefore, the shielding code is prevented from being damaged during installation of the knocking sensor. The use of an impact wrench ensures secure attachment of the sensor, and reduces the installation time.

Abstract: In response to the occurrence of knocking in an internal combustion engine, the basic ignition timing is corrected in a direction to retard it through the charging and discharging of an integrator circuit. The integrated current output of the integrator circuit is varied in accordance with a voltage corresponding to the speed of the engine so as to limit the maximum amount of ignition timing retard at low speeds or high speeds of the engine.

Abstract: An ignition timing control apparatus for an internal combustion engine comprises a pick-up incorporated in a distributor for detecting a crank angle, a circuit for producing a basic ignition timing indicating signal on the basis of the output signal from the pick-up, a knocking detection circuit for generating a knocking detection signal, a circuit responding to the knocking detection signal and the basic ignition timing indicating signal to generate an actual ignition command signal delayed by a predetermined crank angle from the basic ignition timing, and the control apparatus further includes a circuit responding to these three signals to inhibit the operation of the knocking detection circuit during a period beginning at a time point which precedes to the operation of an inlet valve and an exhaust valve of a cylinder another than the cylinder in concern and terminating at a time point at which a predetermined time has elapsed since the ignition of the cylinder in concern.

Abstract: A knocking detector compares an output of a knocking sensor with a reference level derived by integrating and amplifying the output of the knocking sensor to produce a knocking signal. An amplification factor of the amplifier is changed between a low engine rotation speed region and a high engine rotation speed region such that the amplification factor is lower than that at low engine rotational speeds. As a result, the ability to detect knocking is not lowered at high engine rotational speeds so that knocking can be properly detected under all running conditions.

Abstract: A sensor for sensing a property, such as vibration, of a body, which includes an outer hollow tubular sensor casing, having open and closed ends and provided on its outside side with a protuberance adapted for connection to said body, such as by screwing; a base mounting plate mounted across the inner space in the tubular casing; a sensor element for producing an electrical output signal, mounted on the side of the base mounting plate remote from the open end of the tubular casing; an end closing member which closes the open end of the tubular casing; and an electrically conducting sensor lead structure, connected at its one end to the sensor element for receiving a sensor output electrical signal therefrom, and passing, in order therefrom, through an aperture in the base mounting plate, and through an aperture in the end closing member, to the outside of the sensor.

Abstract: A sensor for sensing a property of a body, such as vibration or knocking of an internal combustion engine.