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: 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: 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: 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.

Abstract: A knock detecting apparatus for internal combustion engines is provided with a vibrating rod of a magnetic material having a resonance characteristic in a knock frequency hand of an engine, a free end of the vibrating rod is inserted in a round through hole of a core to form an air gap between the inner surface of the round through hole and the outer surface of the vibrating rod, and the air gas constitutes a portion of a magnetic path between the core and the free end of the vibrating rod. The vibrating rod is allowed to vibrate in more than one directions and air gaps are also formed in respective vibrating directions thereby enabling to detect vibrations due to knock in more than one directions.

Abstract: A vibrator having a resonant frequency within a knocking frequency range forms a part of a magnetic path. The vibrator vibrates in response to the vibration of an internal combustion engine and this changes the reluctance of the magnetic path. The change in the reluctance is sensed by a coil to detect the presence of knock. The vibrator is enclosed with a damper substance consisting of a liquid or sol substance having viscosity of flow properties so that the vibration of the vibrator is restricted and the Q of the resonance characteristic of the vibrator is deteriorated, thus increasing the substantial range of frequency detection of the apparatus. If necessary, the damper substance is heated to maintain its viscosity at a predetermined value.

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 detector device for internal combustion engines comprises a first sensor for sensing the vibrations of an engine within its knocking frequency range, a second sensor for sensing the vibrations of the engine irrespective of the engine knocking frequencies, and a noise suppressing circuit for eliminating the noise in the output signal of the first sensor by means of the output signal of the second sensor.

Abstract: A knock detecting apparatus for internal combustion engines, includes at least two vibration detectors having different resonance characteristics and encased in one container. The vibration detectors are comprised by piezoelectric devices (bimorph cells) or magnetic devices having reed members of magnetic material. The vibration detectors are interconnected by a lead wire to combine the outputs thereof and to produce a cumulative output.

Abstract: A torque detecting system for the internal combustion engines is disclosed. Pressure detecting device is arranged between the engine body and the engine support for detecting the pressure generated between the engine body and the engine support. An electrical circuit generates a torque detection signal in response to a detection signal produced from the pressure detecting device.

Abstract: An ignition timing control system for an internal combustion engine in which an angular position of the internal combustion engine is detected, and on the basis of the signal thus obtained by detection, the ignition timing of the internal combustion engine is determined by calculation in a computing device. A knocking condition is judged by a detection signal produced from a knocking detector of the internal combustion engine, and the ignition timing is corrected by the judgement of knocking. In view of the fact that the knocking occurs only during a certain period of the driving cycle of the internal combustion engine, a knocking condition is judged by comparing a detection signal produced from the knocking detector during the time in the absence of knocking with a detection signal produced during the time in the presence of knocking.

Abstract: A knock detecting apparatus for an internal combustion engine includes a vibrating reed of magnetic material. One end of the vibrating reed is fastened to a supporting member interposing therebetween a magnet and one end of a core. The free end of the vibrating reed confronts with the other end of the core with an air gap therebetween to form a magnetic path including the magnet, vibrating reed, air gap and core. As the vibrating reed vibrates in response to vibration of the engine on which the supporting member is securely mounted, the distance of the air gap changes causing a change in magnetic flux passing through the magnetic path. The change of magnetic flux is detected by a coil wound on the core. The resonance characteristic of the vibrating reed is arranged to fall in the frequency range of the knocking.

Abstract: Method and apparatus is provided for calculating an optimum ignition timing for an internal combustion engine on the basis of values set in dependence on operating conditions of the engine. With a view to prevent ignition times in two successive cycles from differing remarkably from each other, the ignition time or angle for the current cycle is controlled with reference to the ignition time or angle in the just preceding cycle. As one example of the control, in the case where the ignition time electronically anticipated for the current cycle appears to have deviated from the preceding ignition time by more than a predetermined value, the anticipated ignition time is modified to result in the optimum ignition time by adding to or subtracting from the anticipated ignition time a predetermined value. Alternatively, the optimum ignition time may be given by a mean value of the anticipated ignition time and a plurality of the preceding ignition times.

Abstract: It is discriminated in an ignition timing control system for an internal combustion engine whether the ignition timing arithmetically calculated on the basis of sensed operating conditions of the engine lies within a predetermined range of ignition timing. When the result of discrimination indicates that the calculated ignition timing lies within the predetermined range, ignition occurs at that instant, while when the result of discrimination indicates that the calculated ignition timing does not lie within the predetermined range, the result of calculation is disregarded, and ignition occurs at a predetermined instant.

Abstract: An ignition timing control apparatus for an internal combustion engine detects the rotational angle and intake vacuum of the engine to control the ignition timing of the engine in accordance with the computation of computing means on the detected signals, and on the other hand the vibration of the engine is detected to detect the occurrence of knock and thereby to correct the ignition timing in response to the detection of knock.

Abstract: An ignition timing control system is provided with an ignition timing computing unit which determines a maximum acceleration ignition advance .alpha. ACMAX in accordance with an intake pressure difference P and a water temperature T of the engine. When an acceleration is detected by a rapid movement of an acceleration pedal, the maximum acceleration ignition advance is added to the normal ignition advance. Thereafter, the maximum acceleration ignition advance is gradually reduced to zero in accordance with the lapse of time or a change in the engine speed.

Abstract: An ignition control apparatus for an internal combustion engine is disclosed in which the ignition energy for igniting by means of a spark plug the air-fuel mixture supplied to the internal combustion engine is controlled in accordance with the flow velocity of the air-fuel mixture flowing in the neighborhood of the spark plug. An ignition coil for supplying a spark ignition voltage to the spark plug is energized by a power supply and de-energized at the desired timing of spark generation in accordance with the operating conditions of the internal combustion engine. The rotational speed of the engine representing the flow velocity of the mixture is detected and on the basis of this detected rotational speed, the duration of energization of the ignition coil is variably controlled.

Abstract: In normal load operating conditions of the engine, an ignition timing control unit produces an ignition timing signal in accordance with the rotation speed and intake negative pressure of the engine. In transitions, for example, from idling operation to normal load operation, and vice versa, an ignition timing delaying circuit in the ignition timing control unit produces a correction signal by detecting whether or not the throttle valve is fully closed. When the correction signal is produced, the ignition timing control unit produces corrected ignition timing signal so that, in the transient periods of operation, the ignition timing is gradually changed to a predetermined ignition timing.

Abstract: An ignition system for an internal combustion engine comprises knock detecting means for detecting knocking of the engine, and ignition timing control means for controlling the ignition timing of the engine in response to the presence or absence of the knocking condition. The knock detecting means detects the pressure in the cylinders of the engine to detect the occurrence of knocking by the fact that the detected pressure includes a high frequency pressure variation. The ignition timing control means is responsive to the output of the knock detecting means, whereby as long as no knocking is detected the ignition timing is controlled to provide the minimum advance for best torque (MBT) and ensure improved engine power efficiency and fuel consumption, whereas when knocking is detected the ignition timing is retarded in relation to the minimum advance for maximum torque (MBT) to prevent the engine from knocking.