Abstract: An EL element is composed of a glass base plate, a transparent electrode, a dielectric body layer, a luminous body layer, another dielectric body layer and a rear electrode which are piled on each other in order. An an electron inflow restraining layer is formed between the luminous body layer and another dielectric body layer. The luminous body layer is formed by doping Mn into a ZnS crystal and the electron inflow restraining layer is formed by irradiating gas ions of high energy to the surface of the luminous body layer. The electron inflow restraining layer restrains the inflow of electrons supplied to the luminous body layer while being accelerated by an electric field formed between the transparent electrode and the rear electrode.

Abstract: In a knocking detection system for an internal combustion engine, a knocking is detected by a vibration sensor the output level of which is changed by controlling the sensor excitation current. The excitation current is controlled in dependence upon the output of the sensor, engine speed or load conditions or the like so that the output noise level of the sensor is maintained substantially constant regardless of engine operating conditions.

Abstract: A device for the detection of ignition misfire in an internal combustion engine is disclosed. A pressure detector detects changes in the combustion pressure of the engine, and a timing detector calculates a reference angular position of the engine. An ignition/misfire detection unit detects occurrences of ignition/misfire. The detection unit compares the output of the pressure detector with predetermined positive and negative reference voltages, and produces signals when these thresholds are passed. The period of a signal produced from the point of positive value detection to the negative value detection is counted and another period which is double the period from the generation of the positive value to the signal from the timing detector unit is counted. These two signals are then compared against one another, using a predetermined program, to detect if ignition or misfire has occurred in the internal combustion engine.

Abstract: A device for detection of knocking in a diesel engine has a pressure sensor including a piezoelectric element and detecting a rate of change in combustion pressure, an angle sensor for detecting the rotation of the engine or engine speed, and a knocking detector for receiving outputs from the pressure and angle sensors. The knocking detector serves to detect a rate of change in combustion pressure per unit angle upon necessary correction by the engine speed and to compare the obtained rate with a reference rate of 5 atm/deg, at which knocking occurs. Knocking is detected when the detected rate exceeds the reference rate.

Abstract: A device for detecting an abnormality in a pressure detector in an internal combustion engine. This device includes a piezoelectric pressure detector, a timing detection unit, a selective connection unit, and an abnormality detection unit. The abnormality detection unit includes a capacitor connected to an oscillation circuit, and the piezoelectric pressure detector is connected in parallel with the series connection of the oscillation circuit and the capacitor.

Abstract: In a knock detecting apparatus for an internal combustion engine, the output signal of a knock sensor whose output signal level varies in accordance with the engine conditions, engine speed, sensor sensitivity, etc., is passed through an automatic gain control circuit (AGC) thereby stabilizing the output level. The background noise level derived by integrating the output signal and the stabilized output signal are compared to detect the occurrence of knocking. The stabilized output signal is passed through a low-pass filter or a band-pass filter and the resulting control signal is used to control the gain of the AGC circuit.

Abstract: In a feedback type ignition timing control system for internal combustion engines, the predetermined correction advance/retard angle values are stored in a read/write memory at the respective storage areas defined by the respective operating conditions of an engine, and the correction advance/retard angle values are each separately rewritten in accordance with the detected associated engine condition in response to a signal detecting the feedback factor. The advance/retard angle value for the ignition timing corresponding to the detected engine condition is separately determined in accordance with the corresponding rewritten advance/retard angle value and the ignition timing is controlled to suit the respective engine conditions in accordance with the correction advance/retard angle values preliminarily rewritten in response to the feedback factor.

Abstract: A knock detecting apparatus for an internal combustion engine includes a vibrating sheet branched into a plurality of vibrating reeds by forming a recess from one end of the vibrating sheet. The vibrating reeds have different lengths, shapes or thicknesses, and the other end of the vibrating sheet is fixed to a supporting member which is secured to the engine thereby to allow the vibrating reeds to vibrate with different resonance characteristics in response to the vibration of the engine caused by the knocking. The vibration of the vibrating sheet is detected, for example, as a change in reluctance by forming a magnetic path through the vibrating sheet and air gaps respectively located between the free ends of the vibrating reeds and a core.

Abstract: A knock detecting apparatus for detecting the occurrence of knocking in an internal combustion engine by detecting variations in the pressure of engine cooling water. A sealed double diaphragm structure is formed by a first diaphragm which is directly responsive to variations in the cooling water pressure and not resonant at the knock frequencies and a second diaphragm which is resonant at the knock frequencies. A noncompressible fluid is contained in the sealed double diaphragm structure between the two diaphragms. Pulsations of the second diaphragm, resonant at the knock frequencies, are detected by a magnetic device or a piezoelectric device operative to output an ac signal.

Abstract: A method of sensing a knocking taking place in an internal combustion engine through the sensing of pulsative component of the cooling water pressure or lubricating oil pressure. The sensing of the pulsative component is made by removing the static component from the composite pressure which is the sum of the pulsative component and the static component. An apparatus for sensing a knocking taking place in an internal combustion engine has a differential pressure sensing mechanism including a pressure sensing diaphragm and a pulsation absorption mechanism. The pressure sensing diaphragm receives at its one side the composite cooling water pressure or composite lubricating oil pressure which is the sum of the pulsative component and static component. The pulsation absorption mechanism absorbs the pulsative component from the composite pressure so as to transmit only the static component of the pressure to the other side of the pressure sensing diaphragm.

Abstract: An engine knocking detection device has a diaphragm to be disposed in contact with the engine cooling water so as to resonate with pulsations of the pressure of the cooling water caused by engine knockings, and output elements responsive to the vibration of the diaphragm to produce an electrical output signal to be utilized for the control of engine spark timing. The water-contacting surface of the diaphragm is coated with a layer of a hydrophilic material operative to prevent attachment or adhesion of air bubbles to the water-contacting surface of the diaphragm whereby the sensitivity of the diaphragm to the water pressure pulsation is improved.

Abstract: A knocking sensing apparatus for sensing a knocking taking place in an internal combustion engine. The apparatus includes a diaphragm adapted to operate in response to the pressure of cooling water circulated in the engine, magnetism generating device, magnetic circuit including the diaphragm, and a magnetic flux detecting device adapted to detect in a manner like alternating current the change in the magnetic flux in the magnetic circuit caused by the operation of the diaphragm.

Abstract: A knock detecting apparatus includes a vibrating member with a disk-shaped vibrating portion whose resonant point is in the knock frequency range. The outer peripheral edge of the vibrating member is held substantially over the entire periphery. The vibrating portion of the vibrating member may be provided with holes and an addition such as a protrusion and/or a ring-shaped rib portion so as to vary the natural frequency of the vibrating member. Also, the size and shape of the holes and the cross-sectional area of the addition and/or the diameter of the rib portion may be varied to adjust the natural frequency of the vibrating member.

Abstract: An engine knock detecting apparatus having a vibration member with a plate-shaped vibratory portion having a resonance frequency in the frequency range of knocking of the engine. In order to adjust and optimize the degree of peak of the resonance, at least a part of the vibratory portion of the vibration member has a multi-layered structure consisting of two or more layers.

Abstract: A knock detecting apparatus includes a vibrating means having a plate reed member adapted to vibrate in response to the vibrations of an internal combustion engine and a support member which is greater in thickness than the reed member and adapted to support the reed member, the reed and support members being made integrally from a magnetic material. When the reed member resonates upon the occurrence of knocking in the engine, the resulting change in the magnetic reluctance of the magnetic path including the reed member is sensed by a sensing coil to thereby detect the knock. The magnetic flux in the magnetic path is generated by a magnet or an excitation coil. An impedance element may be connected to the sensing coil or the excitation coil so as to correct variations in output from one coil to another.

Abstract: A magnetic path is formed by a vibrating member disposed in a housing in the radial direction and fixed at its end to the housing, a central magnetic path portion which is disposed to make a gap between the vibrating member and the central magnetic portion and to extend in the axial direction of the housing substantially at its center, a radial magnetic path portion extending from the central magnetic path portion in the radial direction of the housing with a predetermined spacing kept from the vibrating member, and an outer peripheral magnetic path portion extending from the outer peripheral side of the radial magnetic path portion toward the vibrating member. A permanent magnet for supplying magnetic flux to the magnetic path is disposed at the central magnetic path portion in the form of bar or at the outer peripheral magnetic path portion in the form of ring or to surround the central magnetic path portion.

Abstract: An ignition timing control apparatus for internal combustion engines is constructed to retard or advance the spark time of an engine when a knocking detector in the ignition timing control apparatus detects the occurrence or non-occurrence of knocking in the engine, respectively, and to retard the spark time by a predetermined angular value irrespective of an output signal from the knocking detector when a failure occurring in the knocking detector has been detected. Further, the ignition timing control apparatus may comprise alarm means which is actuated when a failure occurring in the knocking detector has been detected.

Abstract: A knock detecting apparatus for internal combustion engines includes a housing of a predetermined shape containing therein magnetic circuit means a part of which is formed by vibrating plate means made of a magnetic material and magnetic flux sensing means for sensing a change in the magnetic reluctance of the magnetic circuit means caused by the vibration of the vibrating plate means in resonance with a knocking frequency.

Abstract: The vibrations produced by the knocking in an engine and having frequencies in different frequency bands are detected by a vibration detector having a plurality of resonance frequencies. One of the detection outputs of the vibration detector is selected by a switching circuit or a filter circuit in accordance with the operating conditions of the engine. The ignition timing of the engine is corrected in accordance with the selected detection output.

Abstract: A knock detecting apparatus for an internal combustion engine includes a vibrating sheet branched into a plurality of vibrating reeds by forming a recess from one end of the vibrating sheet. The vibrating reeds have different lengths, shapes or thicknesses, and the other end of the vibrating sheet is fixed to a supporting member which is secured to the engine thereby to allow the vibrating reeds vibrate with different resonance characteristics in response to the vibration of the engine caused by the knocking. The vibration of the vibrating sheet is detected, for examle, as a change in reluctance by forming a magnetic path through the vibrating sheet and air gaps respectively located between the free ends of the vibrating reeds and a core.