An engine-knock controlling system for a carburetor-based engine includes one or more cylinders in which combustion occurs, wherein the system also includes a plurality of knock sensors coupled to an engine block, a first wiring harness, a first control unit, a second wiring harness, and a second control unit or an intermediate control unit, or a second control unit and intermediate control unit. The knock sensor(s) detects threatening engine-knock noise as an audible signal and transmits a signal through the wiring harnesses and control units to generate an ignition retarding action to correct the engine misfire and eliminate the knock/ping. Once the engine knock event is resolved, the processor of the first control unit transmits via the second wiring harness a signal to the second control unit or to the intermediate control unit, or to the second control unit and the intermediate control unit, to allow full-advance of ignition timing.

According to one or more embodiments presently described, a method of operating an internal combustion engine that includes injecting fuel into a combustion chamber to form an air-fuel mixture, where the combustion chamber includes a cylinder head, cylinder sidewalls, and a piston that reciprocates within the cylinder sidewalls. The method may also include detecting pre-ignition of the air-fuel mixture during a detected intake or compression stroke of the piston, determining that a super knock condition could occur, and mitigating formation of a super knock condition by deploying a super knock countermeasure within the detected compression stroke.

A method for checking the association of structure-borne noise sensors of an internal combustion engine having a plurality of cylinders, which internal combustion engine can be operated in diesel operation or with individualized gas injection and in the case of which internal combustion engine a structure-borne noise sensor is arranged in the region of each cylinder, wherein the output signals of the structure-borne noise sensors reflect a knock index and are captured by a computing unit, wherein the internal combustion engine is operated in order to perform the method. The output signals of all structure-borne noise sensors are determined during at least one working cycle, which is formed by two revolutions of a crankshaft, in the respective positions of the crankshaft. The output signal of a cylinder is compared with the average value or the median value of the output signals of other cylinders.

An internal combustion engine knock determining device includes a vibration detector that produces a signal corresponding to engine vibration, an intensity computing unit that retrieves vibrational components in a plurality of frequency regions in which vibration intensity peaks are located when knock occurs, a background-noise computing unit that calculates background noise caused by factors other than knock, a frequency computing unit that determines specific frequency regions from which to determine whether knock is occurring by excluding certain frequency regions designated as frequency regions requiring exclusion due to the intensity of false-detection causing noise as a proportion of the background noise in the certain regions, and a knock determining unit that determines the occurrence of knock based on the vibration intensity in the specific frequency regions obtained by excluding the frequency regions requiring exclusion, wherein the number of specific frequency regions is increased to improve the accuracy of knock detection.

A system includes a controller configured to receive a signal acquired by the at least one knock sensor coupled to a reciprocating device, to sample the received signal, to analyze the sampled signal, and to utilize standard quality control (SQC) techniques to perform real-time diagnostics on the reciprocating device based on the analyzed signal.

In one embodiment, a method is provided. The method includes receiving a plurality of signals representative of an engine noise transmitted via a plurality of noise sensors, wherein the noise sensors are disposed in a grid about an engine. The method further includes receiving a knock sensor signal representative of an engine noise transmitted via a knock sensor. The method additionally includes deriving a combustion event based on the knock sensor signal, and deriving an engine condition based on the plurality of signals and the combustion event. The method also includes communicating the engine condition.

A glow plug includes a cylindrical housing, a rod-shaped heater, a membrane portion, and a pressure sensor. The cylindrical housing extends along an axial direction. The rod-shaped heater extending along the axial direction is displaced along the axial direction and has one end portion disposed within the housing, and an other end portion which is exposed from the housing. The membrane portion connects together the heater and the housing and has a multi-layer construction which has a first layer and a second layer of which at least part is positioned nearer to the other end portion in the axial direction of the heater than the first layer. The pressure sensor measures a pressure within a combustion chamber in which the other end portion is disposed by making use of a displacement of the heater. A thickness of the second layer is larger than a thickness of the first layer.

An engine-knock controlling system for a carburetor-based engine includes one or more cylinders in which combustion occurs, wherein the system also includes a plurality of knock sensors coupled to an engine block, a first wiring harness, a first control unit, a second wiring harness, and a second control unit or an intermediate control unit, or a second control unit and intermediate control unit. The knock sensor(s) detects threatening engine-knock noise as an audible signal and transmits a signal through the wiring harnesses and control units to generate an ignition retarding action to correct the engine misfire and eliminate the knock/ping. Once the engine knock event is resolved, the processor of the first control unit transmits via the second wiring harness a signal to the second control unit or to the intermediate control unit, or to the second control unit and the intermediate control unit, to allow full-advance of ignition timing.

An internal combustion engine has at least one cylinder wall forming a cylinder, and at least one knock sensor held on a housing element. The knock sensor is fixed to a fastening point of the housing element. An intermediate chamber is provided in the radial direction of the cylinder between at least one section of the cylinder wall and the fastening point of the housing element arranged on a side of the cylinder wall facing away from the cylinder, a distance extending at least in the radial direction of the cylinder being provided as a result. At least one sound transmission bridge extends in the intermediate chamber, bridging the distance from the cylinder wall continuously to the fastening point, via which vibrations, on the basis of which knocking combustion can be detected by the knock sensor, are transferrable from the cylinder wall to the fastening point.

Disclosed herein is a method of predicting engine knocking, which includes calculating initial pressure in cylinder based on operating data and pressure in intake manifold measured using manifold absolute pressure sensor, calculating pressure at spark timing in the cylinder by interpreting compression process as polytropic process based on the calculated initial pressure in the cylinder, calculating heat release rate for individual operating conditions based on the calculated pressure in the cylinder at spark timing, calculating pressure change in the cylinder based on the calculated heat release rate, calculating unburned gas temperature in adiabatic compression process based on the calculated pressure change in the cylinder, and determining whether knock occurs by calculating ignition delay based on the calculated unburned gas temperature and calculating unburned gas mass fraction at crank angle at the end of the ignition delay.