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: An ignition timing regulating device for use in an internal combustion engine for regulating the ignition timing of the engine depending on the pressure of ambient atmosphere. Based on the fact that the pressure in the intake manifold of the engine is equal to the pressure of ambient atmosphere in the starting stage of the engine, the output of a pressure sensor sensing the intake manifold pressure in the engine is applied to an atmospheric pressure sensing circuit so as to sense the value of atmospheric pressure in the engine starting stage, and the output of this atmospheric pressure sensing circuit is used for correcting the ignition timing of the engine.

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: 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 method for controlling the ignition timing of internal combustion engines in which the magnitude of knocking is detected for each of at least two different magnitude levels. A knocking signal representing the detected magnitude level of the knocking and produced in each combustion cycle of the engine is sampled for a predetermined number of combustion cycles of the engine, and an ignition timing correction signal is produced to effect either to retard or advance depending on whether the sampled number of the knocking signals is above or below a predetermined reference number.

Abstract: An ignition timing control system for internal combustion engines includes a knock detecting circuit for determining the presence or absence of the knocking in response to a signal from a knock detector, and includes a correction advance computing circuit for computing a correction value of ignition advance thereby to retard the ignition timing by a predetermined angle when the knock is present and to advance the ignition timing when the knock is absent. A further battery is provided to supply electric power to the correction advance computing circuit even after a key switch associated with a main battery for supplying power to the ignition timing control system has been turned off. Hence, the correction advance computing circuit memorizes the computed advance correction value corresponding to a knock condition of the engine just prior to the turn-off of the key switch and the memorized advance correction value is made available in a subsequent operation of the ignition timing control system.

Abstract: An ignition timing control system including a counter into which is introduced a data generated from a memory and indicative of the proper ignition advance corresponding to the operating conditions of an engine and the decrement or increment of the count is made in synchronism with predetermined degrees of rotation of the engine to determine the desired ignition timing. When knock occurs n times per m times of engine explosion stroke, the knocking ratio n/m is computed and the content of the counter is corrected in response to the value of the knocking ratio to correct the ignition timing. The value of m for the knocking ratio n/m is variable in accordance with the engine operating conditions.

Abstract: A method of and apparatus for controlling ignition timing of an internal-combustion engine in accordance with the degree of knocking, the apparatus comprising a knock detector for detecting a vibration corresponding to knocking of the internal-combustion engine, a knock detector circuit responsive to output from the knock detector for detecting the knocking of the internal-combustion engine, and corrective advance computing circuit responsive to an output signal from the knock detector circuit for controlling ignition timing of the engine, wherein the corrective advance computing circuit counts the number of knocks detected during a period of predetermined combustion cycles, compares the number of knocks with a predetermined number, and controls ignition to advance or delay it in accordance with the result of comparison.

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: A knocking detector for an internal combustion engine includes a vibration unit comprising an inertial mass member and springs which are mounted in a housing attached to an engine body. The spring constants of the springs are so selected that the resonant frequency of the vibration unit becomes substantilly equal to the frequency of vibration due to knocking of the engine, and the vibration of the vibration unit is detected and converted into an electric signal.

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.

Abstract: An exposed aggregate finishing method for concrete. The method comprises coating the inside faces of a form for concrete with a cement setting retarder, drying, coating the dried faces with a synthetic organic polymer coating material which is soluble in an aqueous alkaline solution of cement, but is insoluble in water; and drying the coated faces. Alternatively, the method may be carried out by coating the inside faces of the form for concrete with the mixture of the cement setting retarder and the organic polymer coating material and drying the coated faces. Concrete is thereafter placed in the concrete form, the form removed and the surface of the molded concrete washed to make the surface rough.

Abstract: Disclosed is an internal combustion engine comprising a main combustion chamber and an auxiliary combustion chamber which are interconnected to each other via a connecting passage. The opening of the connecting passage is arranged to be directed to the central portion of the piston when the piston reaches the top dead center. The combustible mixture in the auxiliary combustion chamber is ignited. As a result, a burning jet is injected into the main combustion chamber. An additional auxiliary combustion chamber having no spark plug therein is formed in the piston. The additional auxiliary combustion chamber opens onto the central portion of the top face of the piston. The combustible mixture in the additional auxiliary combustion chamber is ignited into an explosion by the burning jet injected from the connecting passage.

Abstract: An ignition system for internal combustion engines wherein an ignition timing computer circuit starts the computation of an ignition timing in response to the detection of a predetermined angular position of the crankshaft of an internal combustion engine by an angular position detector, and an ignition device ignites the engine according to the computed ignition timing. A pressure detector detects variations of the pressure in the cylinders caused by the ignition of the engine and a retard-advance detector determines whether the angular position of the engine crankshaft corresponding to the maximum cylinder pressure agrees with the desired angular position. This retard-advance detector compensates the computation of ignition timing in the ignition timing computer circuit in accordance with its determination.

Abstract: An internal combustion chamber including a main combustion chamber receiving an air-fuel mixture, an auxiliary combustion chamber in communication with the main combustion chamber, and an air supply source for supplying air to the auxiliary combustion chamber. During the suction stroke of an engine piston, an air-fuel mixture is introduced into the main and auxiliary combustion chambers, and additional air from the supply source is fed to the auxiliary combustion chamber.

Abstract: A device for detecting the air-fuel ratio of the mixture supplied to an internal combustion engine of the type including an exhaust gas recirculation system for recirculating a part of the exhaust gas into an intake passage. The device comprises means for detecting the thermal conductivity of the exhaust gas, an electric circuit having a battery which supplies an electric current to said thermal conductivity detecting means and means for measuring the changes of the electric resistance of said thermal conductivity detecting means.

Abstract: The intake valve mechanism employs a back-flow valve to prevent undesirable back-flow of gases from a combustion chamber of an internal combustion engine out an intake port of the chamber during a period of time in which a poppet valve for the intake port of the chamber is open. The back-flow valve is positioned between an intake port valve seat and the intake port poppet valve for blocking the intake port in response to pressure in the combustion chamber. To minimize air-fuel resistance through the intake port, a spring is employed for continuously biasing the back-flow valve to track the movement of the poppet valve, the spring having sufficient strength to prevent the back-flow valve from blocking the intake port when the poppet valve is open until the pressure in the combustion chamber reaches a predetermined value.

Abstract: An internal combustion engine having a main combustion chamber associated with intake and exhaust valves and an auxiliary combustion chamber having no intake valve. The auxiliary combustion chamber is positioned adjacent the intake port and has an electrode of a spark plug or plugs positioned therewithin. A plurality of passages fluidly communicate the main and auxiliary combustion chambers. One passage opens toward the intake valve and at least one other passage opens asymmetrically relative to the first passage about the central axis of the auxiliary combustion chamber. The auxiliary combustion chamber is free of any internal fluid flow obstructions. A stream of sucked gas introduced into the auxiliary combustion chamber through the one passage is turned by the interior walls of the auxiliary combustion chamber to flow in a path in the form of a loop and is then expelled through the other passage.